An analytical procedure for the detection of stimulants, narcotics, β-blockers, β-agonists, and many of their metabolites in urine using a solid-phase extraction procedure and gas chromatography-mass spectrometry (GC-MS) is described. These substances have been specifically banned by the Medical Commission of the International Olympic Committee (IOC) in order to prevent their abuse in sports. Urine samples are submitted to an enzymatic hydrolysis (β-glucuronidase arylsulfatase) and extracted by means of Bond-Elut Certify™ columns. The residues are then selectively derivatized with N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA), which enables the formation of trimethylsilyl derivatives of hydroxyl, acidic, and phenolic groups, and N-methyl-bis-trifluoroacetamide (MBTFA), which enables the formation of trifluoroacetamide derivatives of primary and secondary amines. A GC-MS system working in scan mode is sensitive and specific enough to detect and identify approximately 100 compounds and metabolites in urine for at least 24 h after the administration of doses typically encountered in therapeutics. Detection in selected ion monitoring mode is needed for the determination of β-agonist agents. The method was successfully used in doping control of urine samples during the 25th Olympic Games, July 1992, in Barcelona, Spain. © 1995 Oxford University Press.