An alternative and practical method is described for simultaneous detection and quantification of the potent hallucinogen lysergic acid diethylamide (LSD) and related compounds in urine and serum samples. The procedure is based on liquid-liquid re-extractian with ethyl acetate and reversed-phase liquid chromatography coupled with fluorescence detection (HPLC-FLD). With detection limits in urine and serum samples of ca 0.07 ng mL^-1 for LSD, nor-LSD, and iso-LSD, respectively, the method is well suited to forensic investigations. Application of the method to clinical samples and autopsy material enable selective identification and accurate quantification of LSD and related compounds. Comparison of results with those obtained from an LSD immunoassay (EMIT II) emphasize the need for chromatographic confirmation.