<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><Version>2.4.0.8</Version><ReportLongName>2110100 - Disclosure - Capital Stock</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column FlagID="0"><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><CurrencyCode /><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName /><CurrencySymbol /><contextRef><ContextID>D2013Q3YTD</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0000007032</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2012-09-29T00:00:00</PeriodStartDate><PeriodEndDate>2013-06-28T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS /><CurrencyCode /><OriginalCurrencyCode /></MCU><CurrencySymbol /><Labels><Label Key="CalendarSupplement" Id="0" Label="9 Months Ended" /><Label Key="Calendar" Id="1" Label="Jun. 28, 2013" /></Labels></Column></Columns><Rows><Row FlagID="0"><Id>1</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>1</Level><ElementName>cik0_CapitalStockAbstract</ElementName><ElementPrefix>cik0_</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Capital Stock [Abstract]</Label></Row><Row FlagID="0"><Id>2</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>2</Level><ElementName>cik0_CapitalStockTextBlock</ElementName><ElementPrefix>cik0_</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>terseLabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="D2013Q3YTD" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;div style="font-family:Times New Roman;font-size:10pt;"&gt;&lt;div style="line-height:120%;text-align:left;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;font-weight:bold;text-decoration:underline;"&gt;CAPITAL STOCK&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;font-weight:bold;"&gt;: &lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;padding-top:8px;text-align:left;padding-left:24px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;Pursuant to the Stockholders Agreement of the Parent Company, upon termination of employment from the Company or one of its subsidiaries, members of the Company&amp;#8217;s management (other than Mr.&amp;#160;Neubauer) who hold shares of common stock of the Parent Company can cause the Parent Company to repurchase all of their initial investment shares (as defined) or shares acquired as a result of the exercise of Installment Stock Purchase Opportunities at appraised fair market value. Generally, payment for shares repurchased could be, at the Parent Company&amp;#8217;s option, in cash or installment notes, which would be effectively subordinated to all indebtedness of the Company. The amount of this potential repurchase obligation has been classified outside of shareholder&amp;#8217;s equity, which reflects the Parent Company&amp;#8217;s investment basis and capital structure in the Company&amp;#8217;s condensed consolidated financial statements. The amount of common stock subject to repurchase as of &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;June&amp;#160;28, 2013&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; and &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;September&amp;#160;28, 2012&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; was &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;$153.6 million&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; and &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;$167.5 million&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;, which is based on approximately &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;9.5 million&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; and &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;11.0 million&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; shares of common stock of the Parent Company valued at &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;$16.21&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; and &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;$15.17&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; per share, respectively. The fair value of the common stock subject to repurchase is calculated using discounted cash flow techniques and comparable public company trading multiples. Inputs used in the discounted cash flow analysis include the weighted average cost of capital, long-term revenue growth rates, long-term EBIT margins and residual growth rates. Inputs used in the comparable public company trading multiples include the last-twelve-months' EBITDA multiple, forward EBITDA multiples and control premium. During the &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;nine&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; months ended &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;June&amp;#160;28, 2013&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; and &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;June&amp;#160;29, 2012&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;, approximately &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;$60.2 million&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; and &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;$51.3 million&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt; of common stock of the Parent Company was repurchased, respectively, and has been reflected in the Company&amp;#8217;s condensed consolidated financial statements. The Stockholders Agreement, the senior secured credit agreement and the indenture governing the Senior Notes contain limitations on the amount the Company can expend for such share repurchases.&lt;/font&gt;&lt;/div&gt;&lt;/div&gt;</NonNumbericText><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>nonnum:textBlockItemType</ElementDataType><SimpleDataType>na</SimpleDataType><ElementDefenition>Disclosure of temporary and shareholders' equity, comprised of portions attributable to the parent entity and noncontrolling interest, if any, including, but not limited to: (1) balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings; (2) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, (3) rights and privileges of each class of stock authorized; (4) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (5) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (6) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (7) retained earnings appropriations or restrictions, such as dividend restrictions;  and (8) the potential repurchase obligation of common stock that is classified as temporary equity, including the aggregate amount to be paid upon redemption of the security based on the number of common shares and redemption price per share, the dollar amount of common stock repurchased and other information necessary to a fair presentation.</ElementDefenition><ElementReferences>No definition available.</ElementReferences><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Capital Stock</Label></Row></Rows><Footnotes /><IsEquityReport>false</IsEquityReport><ReportName>Capital Stock</ReportName><MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel><SharesRoundingLevel>UnKnown</SharesRoundingLevel><PerShareRoundingLevel>UnKnown</PerShareRoundingLevel><ExchangeRateRoundingLevel>UnKnown</ExchangeRateRoundingLevel><HasCustomUnits>true</HasCustomUnits><IsEmbedReport>false</IsEmbedReport><IsMultiCurrency>false</IsMultiCurrency><ReportType>Sheet</ReportType><RoleURI>http://www.aramark.com/role/CapitalStock</RoleURI><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows></InstanceReport>
