Abstract Until the first determination of opiates in human hair by GC MS in 1985, radioimmunological results of hair examinations met with opposition. Since then, further GC MS methods have been developed that have led not only to considerably increased sensitivity, but can also be used in hair analysis for screening purposes and can detect substances for which RIA kits are not available. In the present study different extraction methods were used along with two GC MS processes which back-up each other. These methods include the enzymatic dissolution of the hair, incubation with a buffer solution followed by a solid-phase extraction and incubation with methanol without a further extraction. The GC MS examination for heroin, cocaine, hashish and selected pharmaceuticals was carried out after derivatization with pentafluoropropionic acid anhydride or pentafluoro-1-propanol. Because of the higher sensitivity and versatility of GC MS , two GC MS processes were used to confirm each other instead of backing-up radioimmunological measurements with GC MS .