<?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>2115100 - Disclosure - Financial and Other Guarantees</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>4/1/2010 - 12/31/2010
USD ($)

USD ($) / shares
</KeyName><CurrencySymbol>$</CurrencySymbol><contextRef><ContextID>D2011Q3YTD</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0000815065</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2010-04-01T00:00:00</PeriodStartDate><PeriodEndDate>2010-12-31T00:00:00</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>usdPerShare</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="9 Months Ended" /><Label Id="2" Label="Dec. 31, 2010" /></Labels></Column></Columns><Rows><Row><Id>2</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><Level>0</Level><ElementName>ste_NotesToFinancialStatementsAbstract</ElementName><ElementPrefix>ste</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>Notes to Financial Statements [Abstract]</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>Notes to Financial Statements [Abstract]</ElementDefenition><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>Notes To Financial Statements [Abstract]</Label></Row><Row><Id>3</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><Level>0</Level><ElementName>us-gaap_ProductWarrantyDisclosureTextBlock</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>terselabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell><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%;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;font-weight:bold;"&gt;Financial and Other Guarantees&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-indent:20px;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&amp;nbsp;&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-indent:20px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;We generally offer a limited parts and labor warranty on capital equipment. The specific terms and conditions of those warranties vary depending on the product sold and the countries where we conduct business. We record a liability for the estimated cost of product warranties at the time product revenues are recognized. The amounts we expect to incur on behalf of our Customers for the future estimated cost of these warranties are recorded as a current liability on the accompanying Consolidated Balance Sheets. Factors that affect the amount of our warranty liability include the number and type of installed units, historical and anticipated rates of product failures, and material and service costs per claim. We periodically assess the adequacy of our recorded warranty liabilities and adjust the amounts as necessary.&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-indent:20px;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&amp;nbsp;&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-indent:20px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;Changes in our warranty liability during the first nine months of fiscal 2011 were as follows:&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;font-size:9pt;"&gt;&lt;font style="font-family:inherit;font-size:9pt;"&gt;&amp;nbsp;&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;"&gt;&lt;div style="padding-top:10px;"&gt;&lt;table cellpadding="0" cellspacing="0" style="font-family:Times New Roman;font-size:10pt;width:100%;border-collapse:collapse;"&gt;&lt;tr&gt;&lt;td colspan="4" rowspan="1"/&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td width="91%" rowspan="1" colspan="1"/&gt;&lt;td width="1%" rowspan="1" colspan="1"/&gt;&lt;td width="7%" rowspan="1" colspan="1"/&gt;&lt;td width="1%" rowspan="1" colspan="1"/&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;" rowspan="1" colspan="1"&gt;&lt;div style="overflow:hidden;height:20px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&amp;nbsp;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan="3" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;" rowspan="1"&gt;&lt;div style="overflow:hidden;height:20px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&amp;nbsp;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td style="vertical-align:top;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:left;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;Balance, March&#xA0;31, 2010&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;background-color:#cceeff;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:left;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;$&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="vertical-align:bottom;background-color:#cceeff;padding-top:2px;padding-bottom:2px;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:right;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;6,070&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="vertical-align:bottom;background-color:#cceeff;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:left;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&amp;nbsp;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td style="vertical-align:top;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:left;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;Warranties issued during the period&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan="2" style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;" rowspan="1"&gt;&lt;div style="text-align:right;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;2,224&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="vertical-align:bottom;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:left;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&amp;nbsp;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td style="vertical-align:top;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:left;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;Settlements made during the period&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan="2" style="vertical-align:bottom;background-color:#cceeff;padding-left:2px;padding-top:2px;padding-bottom:2px;" rowspan="1"&gt;&lt;div style="text-align:right;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;(1,978&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="vertical-align:bottom;padding-top:2px;padding-bottom:2px;padding-right:2px;background-color:#cceeff;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:left;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;)&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;padding-right:2px;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:left;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;font-weight:bold;"&gt;Balance, December&#xA0;31, 2010&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="vertical-align:bottom;padding-left:2px;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;border-bottom:3px double #000000;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:left;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;$&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="vertical-align:bottom;padding-top:2px;padding-bottom:2px;border-top:1px solid #000000;border-bottom:3px double #000000;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:right;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;6,316&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;td style="vertical-align:bottom;border-top:1px solid #000000;border-bottom:3px double #000000;" rowspan="1" colspan="1"&gt;&lt;div style="text-align:left;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&amp;nbsp;&lt;/font&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;&lt;/div&gt;&lt;/div&gt;&lt;div style="line-height:120%;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&amp;nbsp;&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-indent:20px;font-size:10pt;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;We also sell product maintenance contracts to our Customers. These contracts range in terms from one to five years and require us to maintain and repair the product over the maintenance contract term. We initially record amounts due from Customers under these contracts as a liability for deferred service contract revenue on the accompanying Consolidated Balance Sheets within &#x201C;Accrued expenses and other.&#x201D; The liability recorded for such deferred service revenue was $17,064 and $17,709 as of &lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;color:#000000;text-decoration:none;"&gt;December&#xA0;31, 2010&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;March&#xA0;31, 2010&lt;/font&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;, respectively. Such deferred revenue is then amortized on a straight-line basis over the contract term and recognized as service revenue on our accompanying Consolidated Statements of Income. The activity related to the liability for deferred service contract revenues is excluded from the table presented above.&lt;/font&gt;&lt;/div&gt;&lt;div style="line-height:120%;text-indent:20px;"&gt;&lt;font style="font-family:inherit;font-size:10pt;"&gt;&amp;nbsp;&lt;/font&gt;&lt;/div&gt;&lt;/div&gt;</NonNumbericText><NonNumericTextHeader>Financial and Other Guarantees&amp;nbsp;We generally offer a limited parts and labor warranty on capital equipment. The specific terms and conditions of those</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>Disclosure for standard and extended product warranties and other product guarantee contracts, including a tabular reconciliation of the changes in the guarantor's aggregate product warranty liability for the reporting period.</ElementDefenition><ElementReferences>Reference 1: http://www.xbrl.org/2003/role/presentationRef
 -Publisher FASB
 -Name FASB Interpretation (FIN)
 -Number 45
 -Paragraph 14
 -Subparagraph a, b

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