 <p>I was actually going slightly crazy about this myself. If the data in the csv is encased in quotes, when SSIS imports csv file it includes the quotes in the output of the rows so you actually have to remove the end quotes yourself. Otherwise you are literally trying to cast the quotes and the number to a float. Passing the output of the CSV import to a derived column control will work for you. </p> <p>In the expression field of the derived column -> (DT_R4)REPLACE([Column Name],"\"","")</p> <p>This removes the quotes then cast the value out to a float.</p>