<?xml version="1.0" encoding="utf-8"?>
<InstanceReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Version>1.0.0.3</Version>
  <hasSegments>false</hasSegments>
  <ReportName>Basis of Presentation</ReportName>
  <RoundingOption />
  <Columns>
    <Column>
      <LabelColumn>false</LabelColumn>
      <Id>1</Id>
      <Labels>
        <Label Id="1" Label="6 Months Ended" />
        <Label Id="2" Label="Jun. 30, 2009" />
        <Label Id="4" Label="USD / shares" />
      </Labels>
      <CurrencySymbol>$</CurrencySymbol>
      <hasSegments>false</hasSegments>
      <hasScenarios>false</hasScenarios>
      <Segments />
      <Scenarios />
      <Units>
        <Unit>
          <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>
        </Unit>
        <Unit>
          <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>
        </Unit>
      </Units>
    </Column>
  </Columns>
  <Rows>
    <Row>
      <Id>2</Id>
      <Label>NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS</Label>
      <Level>0</Level>
      <ElementName>wlt_NotesToConsolidatedFinancialsAbstract</ElementName>
      <ElementPrefix>wlt</ElementPrefix>
      <IsBaseElement>false</IsBaseElement>
      <BalanceType>na</BalanceType>
      <PeriodType>duration</PeriodType>
      <ElementDataType>string</ElementDataType>
      <ShortDefinition>No definition available.</ShortDefinition>
      <IsReportTitle>false</IsReportTitle>
      <IsSegmentTitle>false</IsSegmentTitle>
      <IsSubReportEnd>false</IsSubReportEnd>
      <IsCalendarTitle>false</IsCalendarTitle>
      <IsTuple>false</IsTuple>
      <IsAbstractGroupTitle>true</IsAbstractGroupTitle>
      <IsBeginningBalance>false</IsBeginningBalance>
      <IsEndingBalance>false</IsEndingBalance>
      <IsEPS>false</IsEPS>
      <Cells>
        <Cell>
          <Id>1</Id>
          <ShowCurrencySymbol>false</ShowCurrencySymbol>
          <IsNumeric>false</IsNumeric>
          <NumericAmount>0</NumericAmount>
          <RoundedNumericAmount>0</RoundedNumericAmount>
          <NonNumbericText />
          <NonNumericTextHeader />
          <FootnoteIndexer />
          <hasSegments>false</hasSegments>
          <hasScenarios>false</hasScenarios>
        </Cell>
      </Cells>
      <ElementDefenition>No definition available.</ElementDefenition>
      <IsTotalLabel>false</IsTotalLabel>
    </Row>
    <Row>
      <Id>3</Id>
      <Label>Basis of Presentation</Label>
      <Level>1</Level>
      <ElementName>us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock</ElementName>
      <ElementPrefix>us-gaap</ElementPrefix>
      <IsBaseElement>true</IsBaseElement>
      <BalanceType>na</BalanceType>
      <PeriodType>duration</PeriodType>
      <ElementDataType>string</ElementDataType>
      <ShortDefinition>No definition available.</ShortDefinition>
      <IsReportTitle>false</IsReportTitle>
      <IsSegmentTitle>false</IsSegmentTitle>
      <IsSubReportEnd>false</IsSubReportEnd>
      <IsCalendarTitle>false</IsCalendarTitle>
      <IsTuple>false</IsTuple>
      <IsAbstractGroupTitle>false</IsAbstractGroupTitle>
      <IsBeginningBalance>false</IsBeginningBalance>
      <IsEndingBalance>false</IsEndingBalance>
      <IsEPS>false</IsEPS>
      <Cells>
        <Cell>
          <Id>1</Id>
          <ShowCurrencySymbol>false</ShowCurrencySymbol>
          <IsNumeric>false</IsNumeric>
          <NumericAmount>0</NumericAmount>
          <RoundedNumericAmount>0</RoundedNumericAmount>
          <NonNumbericText>&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"&gt;
&lt;HTML&gt;&lt;HEAD&gt;
&lt;META http-equiv=Content-Type content="text/html; charset=utf-8"&gt;
&lt;META content="MSHTML 6.00.6000.16850" name=GENERATOR&gt;&lt;/HEAD&gt;
&lt;BODY&gt;
&lt;P style="FONT-FAMILY: times"&gt;&lt;FONT size=2&gt;&lt;B&gt;Note&amp;nbsp;1&amp;#151;Basis of Presentation
&lt;/B&gt;&lt;/FONT&gt;&lt;/P&gt;
&lt;P style="FONT-FAMILY: times"&gt;&lt;FONT
size=2&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;On April&amp;nbsp;23, 2009,
Walter Industries,&amp;nbsp;Inc. changed its name to Walter Energy,&amp;nbsp;Inc.
("Walter"). Walter, together with its consolidated subsidiaries ("the Company"),
is a leading U.S. producer and exporter of premium metallurgical coal for the
global steel industry (Underground Mining), operates surface mines for the steam
coal and industrial coal markets (Surface Mining) and produces metallurgical
coke (Walter Coke). In December 2008, the Company announced the closure of its
Homebuilding segment and on April&amp;nbsp;17, 2009, the Company spun off its
Financing segment. As a result of the closure and spin-off, amounts previously
reported in those segments are presented as discontinued operations for all
periods presented. See Note&amp;nbsp;2. These actions have completed the
transformation of Walter Industries,&amp;nbsp;Inc. from a diversified corporation to
a pure play natural resources and energy company, now renamed Walter
Energy,&amp;nbsp;Inc. &lt;/FONT&gt;&lt;/P&gt;
&lt;P style="FONT-FAMILY: times"&gt;&lt;FONT
size=2&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;Prior to the first
quarter of 2009, the Company's underground and surface coal mining operations
were reported together as the Natural Resources segment. Beginning with the
first quarter of 2009, the Company revised its reportable segments to separate
the Natural Resources segment into Underground Mining and Surface Mining.
Underground Mining includes the Company's underground metallurgical coal
operations from the No.&amp;nbsp;4 and No.&amp;nbsp;7 mines and its natural gas
operations. Surface Mining includes the Company's surface coal mining operations
for Tuscaloosa Resources,&amp;nbsp;Inc. ("TRI") and Taft Coal Sales&amp;nbsp;&amp;amp;
Associates,&amp;nbsp;Inc. ("Taft") as well as Walter Minerals,&amp;nbsp;Inc. (formerly
known as United Land Corporation) results. In addition, during the second
quarter of 2009 the Company changed the name of its metallurgical coke
manufacturer from Sloss Industries Corporation to Walter Coke,&amp;nbsp;Inc. See
Note&amp;nbsp;9 for segment information. &lt;/FONT&gt;&lt;/P&gt;
&lt;P style="FONT-FAMILY: times"&gt;&lt;FONT
size=2&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;Historically, the Company
has prepared its balance sheet on an unclassified basis because the operating
cycle of Financing exceeded one year. As a result of the spin-off of this
business, the assets and liabilities for continuing operations are now presented
on a classified basis for all periods presented to reflect our current operating
cycle. The assets and liabilities of discontinued operations attributable to
Kodiak and Homebuilding have also been restated to reflect their one-year
operating cycle. The assets and liabilities attributable to Financing continue
to be presented on an unclassified basis. &lt;/FONT&gt;&lt;/P&gt;
&lt;P style="FONT-FAMILY: times"&gt;&lt;FONT
size=2&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;The accompanying
unaudited condensed consolidated financial statements of the Company have been
prepared in accordance with accounting principles generally accepted in the
United States for interim financial information and with the instructions to
Form&amp;nbsp;10-Q and Article&amp;nbsp;10 of Regulation&amp;nbsp;S-X. Accordingly, they do
not include all of the information and footnotes required by accounting
principles generally accepted in the United States for complete financial
statements. In the opinion of management, all adjustments (consisting of normal
recurring accruals) considered necessary for a fair presentation have been
included. Operating results for the three and six months ended June&amp;nbsp;30,
2009 are not necessarily indicative of the results that may be expected for the
year ending December&amp;nbsp;31, 2009. In addition, in accordance with FASB
Statement No.&amp;nbsp;165, &lt;/FONT&gt;&lt;FONT size=2&gt;&lt;I&gt;Subsequent
Events,&lt;/I&gt;&lt;/FONT&gt;&lt;FONT size=2&gt; the accompanying condensed consolidated
financial statements of the Company reflect the evaluation of subsequent events
through the date of this filing. &lt;/FONT&gt;&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;
</NonNumbericText>
          <NonNumericTextHeader>Note&amp;nbsp;1&amp;#151;Basis of Presentation

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;On April&amp;nbsp;23, 2009,
Walter Industries,&amp;nbsp;Inc. changed its name</NonNumericTextHeader>
          <FootnoteIndexer />
          <hasSegments>false</hasSegments>
          <hasScenarios>false</hasScenarios>
        </Cell>
      </Cells>
      <ElementDefenition>No definition available.</ElementDefenition>
      <ElementReferences>No authoritative reference available.</ElementReferences>
      <IsTotalLabel>false</IsTotalLabel>
    </Row>
  </Rows>
  <Footnotes />
  <ComparabilityReport>false</ComparabilityReport>
  <NumberOfCols>1</NumberOfCols>
  <NumberOfRows>2</NumberOfRows>
  <HasScenarios>false</HasScenarios>
  <MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel>
  <SharesRoundingLevel>UnKnown</SharesRoundingLevel>
  <PerShareRoundingLevel>UnKnown</PerShareRoundingLevel>
  <HasPureData>false</HasPureData>
  <SharesShouldBeRounded>true</SharesShouldBeRounded>
</InstanceReport>
