 <p>If it's an older, non-OpenXML version of version of Excel you can use NPOI, it's available for download here:</p> <p><a href="http://npoi.codeplex.com/" rel="nofollow">http://npoi.codeplex.com/</a></p> <pre><code>HSSFWorkbook workbook; using (FileStream fs = new FileStream(sheetfilename + ".xls", FileMode.Open, FileAccess.Read)) { workbook = new HSSFWorkbook(fs); var sheet = workbook.GetSheet("Sheet1"); ...do something.. } </code></pre>