In the literature the values for phospholipid content and the pattern of human gel-filtered platelets diverge considerably. In order to find the possible reasons for these discrepancies, the separation of plasma constituents from gel-filtered platelets and the influence of different extraction methods were reinvestigated. The critical point in phospholipid determination of platelets appeared to be the completeness of plasma lipid separation from platelets and not the extraction method. Avoiding contamination by plasma lipids the results with gel-filtered platelets correlated to that obtained with washed platelets.