<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><Version>2.2.0.25</Version><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><ReportLongName>0212 - Disclosure - Commitments and Contingencies</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelColumn>false</LabelColumn><CurrencyCode>USD</CurrencyCode><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName>1/1/2011 - 3/31/2011
USD ($)

USD ($) / shares
</KeyName><CurrencySymbol>$</CurrencySymbol><contextRef><ContextID>Jan-01-2011_Mar-31-2011</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0001185348</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2011-01-01T00:00:00</PeriodStartDate><PeriodEndDate>2011-03-31T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS><UnitProperty><UnitID>USD</UnitID><UnitType>Standard</UnitType><StandardMeasure><MeasureSchema>http://www.xbrl.org/2003/iso4217</MeasureSchema><MeasureValue>USD</MeasureValue><MeasureNamespace>iso4217</MeasureNamespace></StandardMeasure><Scale>0</Scale></UnitProperty><UnitProperty><UnitID>Shares</UnitID><UnitType>Standard</UnitType><StandardMeasure><MeasureSchema>http://www.xbrl.org/2003/instance</MeasureSchema><MeasureValue>shares</MeasureValue><MeasureNamespace>xbrli</MeasureNamespace></StandardMeasure><Scale>0</Scale></UnitProperty><UnitProperty><UnitID>USDEPS</UnitID><UnitType>Divide</UnitType><NumeratorMeasure><MeasureSchema>http://www.xbrl.org/2003/iso4217</MeasureSchema><MeasureValue>USD</MeasureValue><MeasureNamespace>iso4217</MeasureNamespace></NumeratorMeasure><DenominatorMeasure><MeasureSchema>http://www.xbrl.org/2003/instance</MeasureSchema><MeasureValue>shares</MeasureValue><MeasureNamespace>xbrli</MeasureNamespace></DenominatorMeasure><Scale>0</Scale></UnitProperty></UPS><CurrencyCode>USD</CurrencyCode><OriginalCurrencyCode>USD</OriginalCurrencyCode></MCU><CurrencySymbol>$</CurrencySymbol><Labels><Label Id="1" Label="3 Months Ended" /><Label Id="2" Label="Mar. 31, 2011" /></Labels></Column></Columns><Rows><Row><Id>2</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><Level>0</Level><ElementName>praa_CommitmentsAndContingenciesAbstract</ElementName><ElementPrefix>praa</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>Commitments and Contingencies.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole /><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><NonNumericTextHeader /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>Commitments and Contingencies.</ElementDefenition><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>Commitments and Contingencies [Abstract]</Label></Row><Row><Id>3</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><Level>0</Level><ElementName>us-gaap_CommitmentsAndContingenciesDisclosureTextBlock</ElementName><ElementPrefix>us-gaap</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>No definition available.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>verboselabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;!--DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" --&gt;
   &lt;!-- Begin Block Tagged Note 12 - us-gaap:CommitmentsAndContingenciesDisclosureTextBlock--&gt;
   &lt;div style="font-family: 'Times New Roman',Times,serif"&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 12pt"&gt;&lt;b&gt;12. Commitments and Contingencies:&lt;/b&gt;
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&lt;i&gt;Employment Agreements:&lt;/i&gt;
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The Company has employment agreements, most of which expire on December&amp;#160;31, 2011, with all of
   its executive officers and with several members of its senior management group. Such agreements
   provide for base salary payments as well as bonuses which are based on the attainment of specific
   management goals. Future compensation under these agreements is approximately $10.0&amp;#160;million. The
   agreements also contain confidentiality and non-compete provisions.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 12pt"&gt;&lt;i&gt;Leases:&lt;/i&gt;
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The Company is party to various operating and capital leases with respect to its facilities
   and equipment. For further discussion of these leases please refer to the Company&amp;#8217;s audited
   consolidated financial statements and notes thereto included in the Company&amp;#8217;s Annual Report on Form
   10-K, as filed for the year ended December&amp;#160;31, 2010.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 12pt"&gt;&lt;i&gt;Forward Flow Agreements:&lt;/i&gt;
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The Company is party to several forward flow agreements that allow for the purchase of
   defaulted consumer receivables at pre-established prices. The maximum remaining amount to be
   purchased under forward flow agreements at March&amp;#160;31, 2011 is approximately $148.9&amp;#160;million.
   &lt;/div&gt;
   &lt;!-- Folio --&gt;
   &lt;!-- /Folio --&gt;
   &lt;/div&gt;
   &lt;!-- PAGEBREAK --&gt;
   &lt;div style="font-family: 'Times New Roman',Times,serif"&gt;
   &lt;div align="center" style="font-size: 10pt; margin-top: 0pt"&gt;
   &lt;b&gt;
   &lt;/b&gt;
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 12pt"&gt;&lt;i&gt;Redeemable Noncontrolling Interest:&lt;/i&gt;
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;In connection with the Company&amp;#8217;s acquisition of 62% of the membership units of CCB on March
   15, 2010, the Company acquired the right to purchase the remaining 38% of the membership units of
   CCB not held by the Company at a predetermined price within the next four years. Also, Class
   Action Holdings, Inc. (formerly known as Claims Compensation Bureau, Inc.), the holder of such
   remaining 38% interest in CCB, can require the Company to purchase its interest during the period
   beginning on March&amp;#160;1, 2012 and ending on February&amp;#160;28, 2018. While the actual amount or timing of
   any future payment is unknown at this time, the maximum amount of consideration to be paid for such
   38% interest is $22.8&amp;#160;million.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 12pt"&gt;&lt;i&gt;Litigation:&lt;/i&gt;
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The Company is from time to time subject to routine legal claims and proceedings, most of
   which are incidental to the ordinary course of its business. The Company initiates lawsuits against
   customers and are occasionally countersued by them in such actions. Also, customers, either
   individually, as members of a class action, or through a governmental entity on behalf of
   customers, may initiate litigation against the Company in which they allege that the Company has
   violated a state or federal law in the process of collecting on an account. From time to time,
   other types of lawsuits are brought against the Company. While it is not expected that these or any
   other legal proceedings or claims in which the Company is involved will, either individually or in
   the aggregate, have a material
   adverse impact on the Company&amp;#8217;s results of operations, liquidity or financial condition, it is
   possible that, due to unexpected future developments, an unfavorable resolution of a legal
   proceeding or claim could occur which may be material to the Company&amp;#8217;s results of operations for a
   particular period. The matters described below fall outside of the normal parameters of the
   Company&amp;#8217;s routine legal proceedings.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The Attorney General for the State of Missouri filed a purported enforcement action against
   PRA in 2009 that seeks relief for Missouri customers that have allegedly been injured as a result
   of certain collection practices of PRA. PRA has vehemently denied any wrongdoing herein and in
   2010, the complaint was dismissed with prejudice. In April&amp;#160;2011, the Missouri Court of Appeals
   Eastern District affirmed the prior dismissal. The State of Missouri has since asked the appellate
   court for a rehearing on the matter, or alternatively to have the matter transferred to the
   Missouri Supreme Court. Based on the foregoing, it is not possible at this time to estimate the
   possible loss, if any.
   &lt;/div&gt;
   &lt;div align="left" style="font-size: 10pt; margin-top: 6pt"&gt;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;The Company has recently been named as defendant in the following five putative class action
   cases, each of which alleges that the Company violated the Telephone Consumer Protection Act
   (&amp;#8220;TCPA&amp;#8221;) by calling consumers&amp;#8217; cellular phones without their prior express consent: &lt;i&gt;Allen v.
   Portfolio Recovery Associates, Inc.&lt;/i&gt;, Case No.&amp;#160;10-cv-2658, instituted in the United States District
   Court for the Southern District of California on December&amp;#160;23, 2010; &lt;i&gt;Meyer v. Portfolio Recovery
   Associates, LLC&lt;/i&gt;, Case No.&amp;#160;37-2011-00083047, instituted in the Superior Court of California, San
   Diego County on January&amp;#160;3, 2011; &lt;i&gt;Frydman v. Portfolio Recovery Associates, LLC&lt;/i&gt;, Case No.&amp;#160;11-cv-524,
   instituted in the United States District Court for the Northern District of Illinois on January&amp;#160;31,
   2011; &lt;i&gt;Bartlett v. Portfolio Recovery Associates, LLC&lt;/i&gt;, Case No.&amp;#160;11-cv-0624, instituted in the United
   States District Court for the Northern District of Georgia on March&amp;#160;1, 2011; and &lt;i&gt;Harvey v.
   Portfolio Recovery Associates, LLC&lt;/i&gt;, Case No.&amp;#160;11-cv-00582, instituted in the United States District
   Court for the Middle District of Florida on April&amp;#160;8, 2011. Each of the complaints seeks monetary
   damages under the TCPA, injunctive relief and other relief, including attorney fees. Two of these
   actions, &lt;i&gt;Allen &lt;/i&gt;and &lt;i&gt;Frydman &lt;/i&gt;purport to have been brought on behalf of a national class of
   plaintiffs. The Company has filed a Motion to Dismiss &lt;i&gt;Frydman&lt;/i&gt;, which is currently pending, and the
   complaint in &lt;i&gt;Allen &lt;/i&gt;has not yet been served on the Company. The Company intends to vigorously
   defend against the allegations in each of these cases. It is not possible at this time to estimate
   the possible loss, if any.
   &lt;/div&gt;
   &lt;/div&gt;
</NonNumbericText><NonNumericTextHeader>&lt;!--DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" --&gt;
   &lt;!-- Begin Block Tagged Note</NonNumericTextHeader><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>us-types:textBlockItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>Includes disclosure of commitments and contingencies. This element may be used as a single block of text to encapsulate the entire disclosure including data and tables.</ElementDefenition><ElementReferences>Reference 1: http://www.xbrl.org/2003/role/presentationRef
 -Publisher FASB
 -Name FASB Interpretation (FIN)
 -Number 14
 -Paragraph 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef
 -Publisher FASB
 -Name Statement of Financial Accounting Standard (FAS)
 -Number 5
 -Paragraph 9, 10, 11, 12

</ElementReferences><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>Commitments and Contingencies:</Label></Row></Rows><Footnotes /><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows><ReportName>Commitments and Contingencies</ReportName><MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel><SharesRoundingLevel>UnKnown</SharesRoundingLevel><PerShareRoundingLevel>UnKnown</PerShareRoundingLevel><ExchangeRateRoundingLevel>UnKnown</ExchangeRateRoundingLevel><HasCustomUnits>false</HasCustomUnits><SharesShouldBeRounded>true</SharesShouldBeRounded></InstanceReport>
