485BPOS

		AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON FEBRUARY 15, 2013
		SECURITIES ACT FILE NO. 002-85030
		INVESTMENT COMPANY ACT FILE NO. 811-03851
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM N-1A
REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933:				[X]
Pre-Effective Amendment No.				[  ]
Post-Effective Amendment No. 51				[X]
and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940:				[X]
		Amendment No. 51		[X]
(Check Appropriate Box or Boxes)
NICHOLAS II, INC.
(Exact Name of Registrant as Specified in Charter)
		700 North Water Street
		Milwaukee, WI	53202
		(Address of Principal Executive Offices)	(Zip Code)
Registrant's Telephone Number, Including Area Code (414) 272-4650
Jeffrey T. May, Senior Vice President
Nicholas II, Inc.
700 North Water Street, Suite 1010
Milwaukee, WI 53202
(Name and Address of Agent for Service)
WITH A COPY TO:
K. Thor Lundgren, Esq.
Jason T. Thompson, Esq.
Michael Best & Friedrich LLP
100 East Wisconsin Avenue, Suite 3300
Milwaukee, WI 53202
It is proposed that this filing will become effective (check appropriate box):
[  x  ]		Immediately upon filing pursuant to paragraph (b) of Rule 485.
[	]	On (date) pursuant to paragraph (b) of Rule 485.
[	]	60 days after filing pursuant to paragraph (a)(1) of Rule 485.
[	]	On (date) pursuant to paragraph (a)(1) of Rule 485.
[	]	75 days after filing pursuant to paragraph (a)(2) of Rule 485.
[	]	On (date) pursuant to paragraph (a)(2) of Rule 485.
If appropriate, check the following box:
[	]	This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, each as amended, the Registrant certifies that it meets all of the requirements for effectiveness of the registration statement under Rule 485(b) under the Securities Act of 1933, as amended, and has duly caused this Registration Statement to be signed below on its behalf by the undersigned, thereunto duly authorized, in the City of Milwaukee and State of Wisconsin, on the 15^th day of February, 2013.

Nicholas II, Inc.
By:	/s/ Jeffrey T. May
	Jeffrey T. May, Senior Vice President, Secretary,
	Treasurer and Principal
	Financial and Accounting Officer

     Pursuant to the requirements of the Securities Act of 1933, as amended, this Amendment to the Registration Statement has been signed below by the following persons in the capacities indicated on the 15^th day of February, 2013.

/s/	David O. Nicholas*	President (Chief Executive
	David O. Nicholas	Officer), and Director
/s/	Robert H. Bock*	Director
	Robert H. Bock
/s/	Jay H. Robertson*	Director
	Jay H. Robertson
/s/	Timothy P. Reiland*	Director
	Timothy P. Reiland
* By: /s/ Jeffrey T. May
	Jeffrey T. May,
	Attorney-in-Fact pursuant to
	Power of Attorney previously filed.

EXHIBIT INDEX

Exhibit	Exhibit No.
XBRL Instance Document	EX-101.INS
XBRL Taxonomy Extension Schema Document	EX-101.SCH
XBRL Taxonomy Extension Calculation Linkbase	EX-101.CAL
XBRL Taxonomy Extension Definition Linkbase	EX-101.DEF
XBRL Taxonomy Extension Labels Linkbase	EX-101.LAB
XBRL Taxonomy Extension Presentation Linkbase	EX-101.PRE

XML

Class N | NICHOLAS II INC

Investment Objective

The Fund strives to increase the value of your investment over the long-term (“long-term growth”).

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(fees paid directly from your investment)

Shareholder Fees (USD $)	Class N NICHOLAS II INC CLASS N
Maximum Sales Charge (Load) Imposed on Purchases	none
Maximum Deferred Sales Charge (Load)	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends	none
Wire Redemption Fee	15.00
Exchange Fee	none

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Class N NICHOLAS II INC CLASS N
Management Fees	0.53%
Distribution (12b-1) Fees	0.25%
Other Expenses	0.21%
Total Annual Fund Operating Expenses	0.99%

Example:

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.
The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same.
Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Expense Example (USD $)	One Year	Three Years	Five Years	Ten Years
Class N NICHOLAS II INC CLASS N	101	315	547	1,213

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 22.70% of the average value of the portfolio.

Principal Investment Strategies

To pursue the Fund’s investment objective of long-term growth, it primarily invests in common stocks of domestic corporations with medium-sized market capitalizations believed to have growth potential. The Fund believes a company’s annual sales volume and the market capitalization (the number of shares outstanding multiplied by the per share price) are the factors most illustrative of a company’s size. In distinguishing company size in terms of sales volume, the Fund considers a company’s sales volume relative to peer companies in the company’s industry. In terms of market capitalization, the Fund generally considers companies with market capitalizations up to $2 billion as “small,” between $2 billion and $10 billion as “medium,” and greater than $10 billion as “large.” To a lesser extent, the Fund may invest in companies with small and large market capitalizations. The Fund looks for established companies with the potential for superior growth in sales and earnings in a diversified group of industries. The Fund’s investment philosophy is basically a long-term growth philosophy, based upon the assumption that if a company achieves superior growth in sales and earnings, eventually the company’s stock will achieve superior performance. It is anticipated that a major portion of the Fund’s portfolio will be invested in common stocks of the types of companies, and in the manner, as described above.

Principal Risks of Investing

As with any mutual fund, the Fund cannot guarantee that it will achieve its goals or that its performance will be positive over any period of time. The Fund’s investments change in value. Consequently, the value of your Fund shares may change. If the value of the Fund shares or the values of the Fund’s investments go down, you may lose money.

The principal risks of investing in the Fund are:

• Market Risk – Market risk involves the possibility that the value of the Fund’s investments will fluctuate as the stock market fluctuates over short- or longer-term periods. Common stock prices tend to be more volatile than other investment choices.

• Portfolio-Specific Risk – From time to time, the value of an individual company may decline due to a particular set of circumstances affecting that company, its industry or certain companies within the industry, while having little or no impact on other similar companies within the industry. Because the Fund will invest most of its assets in the securities of mid-cap companies and to a lesser extent, small-cap companies, the Fund may face additional risks. Small- to mid- cap companies often have a limited market for their securities and limited financial resources, and are usually more affected by changes in the economy. Securities of small to medium capitalization companies also often fluctuate in price more than common stocks of larger capitalization companies.

• Selection Risk – The Fund also faces selection risk, which is the risk that the stocks the Fund purchases will underperform markets or other mutual funds with similar investment objectives and strategies.

Since there are risks inherent in all investments in securities, there is no assurance that the Fund’s objectives will be achieved.

Performance

Class N shares of the Fund were first offered for sale on February 28, 2005; therefore, the performance information shown for periods prior to February 28, 2005 represents the performance for the original share class of the Fund, the Class I shares. Nicholas II ? Class I shares were first offered for sale on October 17, 1983.

The bar chart shown below provides some indication of the risks of investing in the Fund. The chart shows the variability of the total return of the Fund?s shares for the last ten calendar years(1). Updated performance information for the Fund is available on our website at www.nicholasfunds.com.

Nicholas II, Inc. – Class N linked to Class I

For the ten calendar year periods shown in the above bar chart, the highest quarterly return was 15.32% (for the quarter ended June 30, 2003) and the lowest quarterly return was -21.54% (for the quarter ended December 31, 2008).

This next table shows how the average annual total returns for the Fund’s Class N shares linked to Class I shares for the one, five and ten year periods ending on December 31, 2012 (the Fund’s most recently completed calendar year), compared to the returns of broad measures of market performance and the performance average of similar mutual funds. The table also shows the average annual total returns for the Fund after taxes on distributions and after taxes on distributions and the redemption of all of your Fund shares. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Updated performance information for the Fund is available on our website at www.nicholasfunds.com.

Average Annual Total Returns Class N NICHOLAS II INC	One Year	Five Year	Ten Year
CLASS N	14.45%	4.24%	8.30%
CLASS N Return After Taxes on Distributions	13.00%	3.56%	7.48%
CLASS N Return After Taxes on Distributions and Sale of Fund Shares	11.28%	3.52%	7.19%
Russell Midcap Growth Index (reflects no deduction for fees, expenses or taxes)	15.81%	3.23%	10.32%
Russell Midcap Index (reflects no deduction for fees, expenses or taxes)	17.28%	3.57%	10.65%
Morningstar Mid-Cap Growth Category (reflects no deduction for taxes)	14.07%	1.74%	8.98%

Of course, the Fund’s past performance (before and after taxes) is no guarantee of its future returns.

[1] The Fund's fiscal year end is September 30. As reflected in the bar chart, the Fund's year-to-date return as of December 31, 2012 was 14.45%.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	NICHOLAS II INC
Prospectus Date	rr_ProspectusDate	Jan. 28, 2013
Class I | NICHOLAS II INC
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	SUMMARY – NICHOLAS II, INC.
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund strives to increase the value of your investment over the long-term (“long-term growth”).
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 22.70% of the average value of the portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	22.70%
Expense Example [Heading]	rr_ExpenseExampleHeading	Example:
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	To pursue the Fund’s investment objective of long-term growth, it primarily invests in common stocks of domestic corporations with medium-sized market capitalizations believed to have growth potential. The Fund believes a company’s annual sales volume and the market capitalization (the number of shares outstanding multiplied by the per share price) are the factors most illustrative of a company’s size. In distinguishing company size in terms of sales volume, the Fund considers a company’s sales volume relative to peer companies in the company’s industry. In terms of market capitalization, the Fund generally considers companies with market capitalizations up to $2 billion as“small,” between $2 billion and $10 billion as “medium,” and greater than $10 billion as “large.” To a lesser extent, the Fund may invest in companies with small and large market capitalizations. The Fund looks for established companies with the potential for superior growth in sales and earnings in a diversified group of industries. The Fund’s investment philosophy is basically a long-term growth philosophy, based upon the assumption that if a company achieves superior growth in sales and earnings, eventually the company’s stock will achieve superior performance. It is anticipated that a major portion of the Fund’s portfolio will be invested in common stocks of the types of companies, and in the manner, as described above.
Risk [Heading]	rr_RiskHeading	Principal Risks of Investing
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any mutual fund, the Fund cannot guarantee that it will achieve its goals or that its performance will be positive over any period of time. The Fund’s investments change in value. Consequently, the value of your Fund shares may change. If the value of the Fund shares or the values of the Fund’s investments go down, you may lose money. The principal risks of investing in the Fund are: Market Risk – Market risk involves the possibility that the value of the Fund’s investments will fluctuate as the stock market fluctuates over short- or longer-term periods. Common stocks prices tend to be more volatile than other investments choices. Portfolio-Specific Risk – From time to time, the value of an individual company may decline due to a particular set of circumstances affecting that company, its industry or certain companies within the industry, while having little or no impact on other similar companies within the industry. Because the Fund will invest most of its assets in the securities of mid-cap companies and to a lesser extent, small-cap companies, the Fund may face additional risks. Small- to mid- cap companies often have a limited market for their securities and limited financial resources, and are usually more affected by changes in the economy. Securities of small to medium capitalization companies also often fluctuate in price more than common stocks of larger capitalization companies. Selection Risk – The Fund also faces selection risk, which is the risk that the stocks the Fund purchases will underperform markets or other mutual funds with similar investment objectives and strategies. Since there are risks inherent in all investments in securities, there is no assurance that the Fund’s objectives will be achieved.
Risk Lose Money [Text]	rr_RiskLoseMoney	If the value of the Fund shares or the values of the Fund’s investments go down, you may lose money.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart shown below provides some indication of the risks of investing in the Fund. The chart shows the variability of the Fund’s total return for the last ten calendar years(1). Updated performance information for the Fund is available on our website at www.nicholasfunds.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The chart shows the variability of the Fund’s total return for the last ten calendar years(1).
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.nicholasfunds.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	Of course, the Fund’s past performance (before and after taxes) is no guarantee of its future returns.
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	For the ten calendar year periods shown in the above bar chart, the highest quarterly return was 15.32% (for the quarter ended June 30, 2003) and the lowest quarterly return was -21.41% (for the quarter ended December 31, 2008).
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	This next table shows how the Fund’s average annual total returns for the one, five and ten year periods ending on December 31, 2012 (the Fund’s most recently completed calendar year), compared to the returns of broad measures of market performance and the performance average of similar mutual funds. The table also shows the Fund’s average annual total returns after taxes on distributions and after taxes on distributions and the redemption of all of your Fund shares. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Class I | NICHOLAS II INC | CLASS I
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load)	rr_MaximumDeferredSalesChargeOverOfferingPrice	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Exchange Fee	rr_ExchangeFee	none
Wire Redemption Fee	rr_ShareholderFeeOther	15
Management Fees	rr_ManagementFeesOverAssets	0.53%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	0.11%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.64%
One Year	rr_ExpenseExampleYear01	65
Three Years	rr_ExpenseExampleYear03	205
Five Years	rr_ExpenseExampleYear05	357
Ten Years	rr_ExpenseExampleYear10	798
2003	rr_AnnualReturn2003	33.30%	[1]
2004	rr_AnnualReturn2004	12.03%	[1]
2005	rr_AnnualReturn2005	5.94%	[1]
2006	rr_AnnualReturn2006	8.25%	[1]
2007	rr_AnnualReturn2007	6.40%	[1]
2008	rr_AnnualReturn2008	(30.77%)	[1]
2009	rr_AnnualReturn2009	29.08%	[1]
2010	rr_AnnualReturn2010	21.94%	[1]
2011	rr_AnnualReturn2011	0.01%	[1]
2012	rr_AnnualReturn2012	14.84%	[1]
Year to Date Return, Label	rr_YearToDateReturnLabel	Fund’s year-to-date return as of December 31, 2012
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Dec. 31, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	14.84%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest quarterly return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2003
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	15.32%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest quarterly return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(21.41%)
One Year	rr_AverageAnnualReturnYear01	14.84%
Five Year	rr_AverageAnnualReturnYear05	4.59%
Ten Year	rr_AverageAnnualReturnYear10	8.59%
Class I | NICHOLAS II INC | Return After Taxes on Distributions | CLASS I
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	13.34%
Five Year	rr_AverageAnnualReturnYear05	3.87%
Ten Year	rr_AverageAnnualReturnYear10	7.74%
Class I | NICHOLAS II INC | Return After Taxes on Distributions and Sale of Fund Shares | CLASS I
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	11.60%
Five Year	rr_AverageAnnualReturnYear05	3.81%
Ten Year	rr_AverageAnnualReturnYear10	7.44%
Class I | NICHOLAS II INC | Russell Midcap Growth Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	15.81%
Five Year	rr_AverageAnnualReturnYear05	3.23%
Ten Year	rr_AverageAnnualReturnYear10	10.32%
Class I | NICHOLAS II INC | Russell Midcap Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	17.28%
Five Year	rr_AverageAnnualReturnYear05	3.57%
Ten Year	rr_AverageAnnualReturnYear10	10.65%
Class I | NICHOLAS II INC | Morningstar Mid-Cap Growth Category (reflects no deduction for taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	14.07%
Five Year	rr_AverageAnnualReturnYear05	1.74%
Ten Year	rr_AverageAnnualReturnYear10	8.98%

[1] The Fund's fiscal year end is September 30. As reflected in the bar chart, the Fund's year-to-date return as of December 31, 2012 was 14.84%.

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Class I | NICHOLAS II INC

SUMMARY – NICHOLAS II, INC.

Investment Objective

The Fund strives to increase the value of your investment over the long-term (“long-term growth”).

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund.

Shareholder Fees

(fees paid directly from your investment)

Shareholder Fees (USD $)	Class I NICHOLAS II INC CLASS I
Maximum Sales Charge (Load) Imposed on Purchases	none
Maximum Deferred Sales Charge (Load)	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends	none
Wire Redemption Fee	15
Exchange Fee	none

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses	Class I NICHOLAS II INC CLASS I
Management Fees	0.53%
Distribution (12b-1) Fees	none
Other Expenses	0.11%
Total Annual Fund Operating Expenses	0.64%

Example:

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.
The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same.
Although your actual costs may be higher or lower, based on these assumptions, your costs would be:

Expense Example (USD $)	One Year	Three Years	Five Years	Ten Years
Class I NICHOLAS II INC CLASS I	65	205	357	798

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 22.70% of the average value of the portfolio.

Principal Investment Strategies

To pursue the Fund’s investment objective of long-term growth, it primarily invests in common stocks of domestic corporations with medium-sized market capitalizations believed to have growth potential. The Fund believes a company’s annual sales volume and the market capitalization (the number of shares outstanding multiplied by the per share price) are the factors most illustrative of a company’s size. In distinguishing company size in terms of sales volume, the Fund considers a company’s sales volume relative to peer companies in the company’s industry. In terms of market capitalization, the Fund generally considers companies with market capitalizations up to $2 billion as“small,” between $2 billion and $10 billion as “medium,” and greater than $10 billion as “large.” To a lesser extent, the Fund may invest in companies with small and large market capitalizations. The Fund looks for established companies with the potential for superior growth in sales and earnings in a diversified group of industries. The Fund’s investment philosophy is basically a long-term growth philosophy, based upon the assumption that if a company achieves superior growth in sales and earnings, eventually the company’s stock will achieve superior performance. It is anticipated that a major portion of the Fund’s portfolio will be invested in common stocks of the types of companies, and in the manner, as described above.

Principal Risks of Investing

As with any mutual fund, the Fund cannot guarantee that it will achieve its goals or that its performance will be positive over any period of time. The Fund’s investments change in value. Consequently, the value of your Fund shares may change. If the value of the Fund shares or the values of the Fund’s investments go down, you may lose money.

The principal risks of investing in the Fund are:

• Market Risk – Market risk involves the possibility that the value of the Fund’s investments will fluctuate as the stock market fluctuates over short- or longer-term periods. Common stocks prices tend to be more volatile than other investments choices.

• Portfolio-Specific Risk – From time to time, the value of an individual company may decline due to a particular set of circumstances affecting that company, its industry or certain companies within the industry, while having little or no impact on other similar companies within the industry. Because the Fund will invest most of its assets in the securities of mid-cap companies and to a lesser extent, small-cap companies, the Fund may face additional risks. Small- to mid- cap companies often have a limited market for their securities and limited financial resources, and are usually more affected by changes in the economy. Securities of small to medium capitalization companies also often fluctuate in price more than common stocks of larger capitalization companies.

• Selection Risk – The Fund also faces selection risk, which is the risk that the stocks the Fund purchases will underperform markets or other mutual funds with similar investment objectives and strategies.

Since there are risks inherent in all investments in securities, there is no assurance that the Fund’s objectives will be achieved.

Performance

The bar chart shown below provides some indication of the risks of investing in the Fund. The chart shows the variability of the Fund’s total return for the last ten calendar years⁽¹⁾. Updated performance information for the Fund is available on our website at www.nicholasfunds.com.

For the ten calendar year periods shown in the above bar chart, the highest quarterly return was 15.32% (for the quarter ended June 30, 2003) and the lowest quarterly return was -21.41% (for the quarter ended December 31, 2008).

This next table shows how the Fund’s average annual total returns for the one, five and ten year periods ending on December 31, 2012 (the Fund’s most recently completed calendar year), compared to the returns of broad measures of market performance and the performance average of similar mutual funds. The table also shows the Fund’s average annual total returns after taxes on distributions and after taxes on distributions and the redemption of all of your Fund shares. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Average Annual Total Returns Class I NICHOLAS II INC	One Year	Five Year	Ten Year
CLASS I	14.84%	4.59%	8.59%
CLASS I Return After Taxes on Distributions	13.34%	3.87%	7.74%
CLASS I Return After Taxes on Distributions and Sale of Fund Shares	11.60%	3.81%	7.44%
Russell Midcap Growth Index (reflects no deduction for fees, expenses or taxes)	15.81%	3.23%	10.32%
Russell Midcap Index (reflects no deduction for fees, expenses or taxes)	17.28%	3.57%	10.65%
Morningstar Mid-Cap Growth Category (reflects no deduction for taxes)	14.07%	1.74%	8.98%

Of course, the Fund’s past performance (before and after taxes) is no guarantee of its future returns.

[1] The Fund's fiscal year end is September 30. As reflected in the bar chart, the Fund's year-to-date return as of December 31, 2012 was 14.84%.

XML

Document and Entity Information	12 Months Ended
	Jan. 28, 2013
Risk/Return:
Document Type	485BPOS
Document Period End Date	Sep. 30, 2012
Registrant Name	NICHOLAS II INC
Central Index Key	0000723455
Amendment Flag	false
Document Creation Date	Jan. 28, 2013
Document Effective Date	Jan. 28, 2013
Prospectus Date	Jan. 28, 2013

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	NICHOLAS II INC
Prospectus Date	rr_ProspectusDate	Jan. 28, 2013
Class N | NICHOLAS II INC
Risk/Return:	rr_RiskReturnAbstract
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Fund strives to increase the value of your investment over the long-term (“long-term growth”).
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses of the Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The table below describes the fees and expenses that you may pay if you buy and hold shares of the Fund.
Shareholder Fees Caption [Text]	rr_ShareholderFeesCaption	Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 22.70% of the average value of the portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	22.70%
Expense Example [Heading]	rr_ExpenseExampleHeading	Example:
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	To pursue the Fund’s investment objective of long-term growth, it primarily invests in common stocks of domestic corporations with medium-sized market capitalizations believed to have growth potential. The Fund believes a company’s annual sales volume and the market capitalization (the number of shares outstanding multiplied by the per share price) are the factors most illustrative of a company’s size. In distinguishing company size in terms of sales volume, the Fund considers a company’s sales volume relative to peer companies in the company’s industry. In terms of market capitalization, the Fund generally considers companies with market capitalizations up to $2 billion as “small,” between $2 billion and $10 billion as “medium,” and greater than $10 billion as “large.” To a lesser extent, the Fund may invest in companies with small and large market capitalizations. The Fund looks for established companies with the potential for superior growth in sales and earnings in a diversified group of industries. The Fund’s investment philosophy is basically a long-term growth philosophy, based upon the assumption that if a company achieves superior growth in sales and earnings, eventually the company’s stock will achieve superior performance. It is anticipated that a major portion of the Fund’s portfolio will be invested in common stocks of the types of companies, and in the manner, as described above.
Risk [Heading]	rr_RiskHeading	Principal Risks of Investing
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	As with any mutual fund, the Fund cannot guarantee that it will achieve its goals or that its performance will be positive over any period of time. The Fund’s investments change in value. Consequently, the value of your Fund shares may change. If the value of the Fund shares or the values of the Fund’s investments go down, you may lose money. The principal risks of investing in the Fund are: Market Risk – Market risk involves the possibility that the value of the Fund’s investments will fluctuate as the stock market fluctuates over short- or longer-term periods. Common stock prices tend to be more volatile than other investment choices. Portfolio-Specific Risk – From time to time, the value of an individual company may decline due to a particular set of circumstances affecting that company, its industry or certain companies within the industry, while having little or no impact on other similar companies within the industry. Because the Fund will invest most of its assets in the securities of mid-cap companies and to a lesser extent, small-cap companies, the Fund may face additional risks. Small- to mid- cap companies often have a limited market for their securities and limited financial resources, and are usually more affected by changes in the economy. Securities of small to medium capitalization companies also often fluctuate in price more than common stocks of larger capitalization companies. Selection Risk – The Fund also faces selection risk, which is the risk that the stocks the Fund purchases will underperform markets or other mutual funds with similar investment objectives and strategies. Since there are risks inherent in all investments in securities, there is no assurance that the Fund’s objectives will be achieved.
Risk Lose Money [Text]	rr_RiskLoseMoney	If the value of the Fund shares or the values of the Fund’s investments go down, you may lose money.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	Class N shares of the Fund were first offered for sale on February 28, 2005; therefore, the performance information shown for periods prior to February 28, 2005 represents the performance for the original share class of the Fund, the Class I shares. Nicholas II ? Class I shares were first offered for sale on October 17, 1983. The bar chart shown below provides some indication of the risks of investing in the Fund. The chart shows the variability of the total return of the Fund?s shares for the last ten calendar years(1). Updated performance information for the Fund is available on our website at www.nicholasfunds.com.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart shown below provides some indication of the risks of investing in the Fund. The chart shows the variability of the total return of the Fund’s shares for the last ten calendar years(1).
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.nicholasfunds.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	Of course, the Fund’s past performance (before and after taxes) is no guarantee of its future returns.
Bar Chart [Heading]	rr_BarChartHeading	Nicholas II, Inc. – Class N linked to Class I
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	For the ten calendar year periods shown in the above bar chart, the highest quarterly return was 15.32% (for the quarter ended June 30, 2003) and the lowest quarterly return was -21.54% (for the quarter ended December 31, 2008).
Bar Chart, Returns for Class Not Offered in Prospectus [Text]	rr_BarChartReturnsForClassNotOfferedInProspectus	Class N shares of the Fund were first offered for sale on February 28, 2005; therefore, the performance information shown for periods prior to February 28, 2005 represents the performance for the original share class of the Fund, the Class I shares.
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	This next table shows how the average annual total returns for the Fund’s Class N shares linked to Class I shares for the one, five and ten year periods ending on December 31, 2012 (the Fund’s most recently completed calendar year), compared to the returns of broad measures of market performance and the performance average of similar mutual funds. The table also shows the average annual total returns for the Fund after taxes on distributions and after taxes on distributions and the redemption of all of your Fund shares. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Updated performance information for the Fund is available on our website at www.nicholasfunds.com.
Class N | NICHOLAS II INC | CLASS N
Risk/Return:	rr_RiskReturnAbstract
Maximum Sales Charge (Load) Imposed on Purchases	rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice	none
Maximum Deferred Sales Charge (Load)	rr_MaximumDeferredSalesChargeOverOfferingPrice	none
Maximum Sales Charge (Load) Imposed on Reinvested Dividends	rr_MaximumSalesChargeOnReinvestedDividendsAndDistributionsOverOther	none
Exchange Fee	rr_ExchangeFee	none
Wire Redemption Fee	rr_ShareholderFeeOther	15.00
Management Fees	rr_ManagementFeesOverAssets	0.53%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	0.25%
Other Expenses	rr_OtherExpensesOverAssets	0.21%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.99%
One Year	rr_ExpenseExampleYear01	101
Three Years	rr_ExpenseExampleYear03	315
Five Years	rr_ExpenseExampleYear05	547
Ten Years	rr_ExpenseExampleYear10	1,213
2003	rr_AnnualReturn2003	33.30%	[1]
2004	rr_AnnualReturn2004	12.03%	[1]
2005	rr_AnnualReturn2005	5.63%	[1]
2006	rr_AnnualReturn2006	7.89%	[1]
2007	rr_AnnualReturn2007	5.97%	[1]
2008	rr_AnnualReturn2008	(31.03%)	[1]
2009	rr_AnnualReturn2009	28.79%	[1]
2010	rr_AnnualReturn2010	21.55%	[1]
2011	rr_AnnualReturn2011	(0.38%)	[1]
2012	rr_AnnualReturn2012	14.45%	[1]
Year to Date Return, Label	rr_YearToDateReturnLabel	Fund’s year-to-date return as of December 31, 2012
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Dec. 31, 2012
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	14.45%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest quarterly return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2003
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	15.32%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest quarterly return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(21.54%)
One Year	rr_AverageAnnualReturnYear01	14.45%
Five Year	rr_AverageAnnualReturnYear05	4.24%
Ten Year	rr_AverageAnnualReturnYear10	8.30%
Class N | NICHOLAS II INC | Return After Taxes on Distributions | CLASS N
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	13.00%
Five Year	rr_AverageAnnualReturnYear05	3.56%
Ten Year	rr_AverageAnnualReturnYear10	7.48%
Class N | NICHOLAS II INC | Return After Taxes on Distributions and Sale of Fund Shares | CLASS N
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	11.28%
Five Year	rr_AverageAnnualReturnYear05	3.52%
Ten Year	rr_AverageAnnualReturnYear10	7.19%
Class N | NICHOLAS II INC | Russell Midcap Growth Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	15.81%
Five Year	rr_AverageAnnualReturnYear05	3.23%
Ten Year	rr_AverageAnnualReturnYear10	10.32%
Class N | NICHOLAS II INC | Russell Midcap Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	17.28%
Five Year	rr_AverageAnnualReturnYear05	3.57%
Ten Year	rr_AverageAnnualReturnYear10	10.65%
Class N | NICHOLAS II INC | Morningstar Mid-Cap Growth Category (reflects no deduction for taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	14.07%
Five Year	rr_AverageAnnualReturnYear05	1.74%
Ten Year	rr_AverageAnnualReturnYear10	8.98%

[1] The Fund's fiscal year end is September 30. As reflected in the bar chart, the Fund's year-to-date return as of December 31, 2012 was 14.45%.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	NICHOLAS II INC
Prospectus Date	rr_ProspectusDate	Jan. 28, 2013
Document Creation Date	dei_DocumentCreationDate	Jan. 28, 2013