Hair of young subjects (N = 36) suspected for drug abuse was analysed for morphine, codeine, heroin, 6-acetylmorphine, cocaine, methadone, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyethylamphetamine (MDEA). The analysis of morphine, codeine, heroin, 6-acetylmorphine, cocaine, and methadone in hair included incubation in methanol, solid-phase extraction, derivatisation by the mixture of propionic acid anhydride and pyridine, and gas chromatography/mass spectrometry (GC/MS). For amphetamine, methamphetamine, MDA, MDMA, and MDEA analysis, hair samples were incubated in 1M sodium hydroxide, extracted with ethyl acetate, derivatised with heptafluorobutyric acid anhydride (HFBA), and assayed by GC/MS. The methods were reproducible (R.S.D. = 5.0-16.1%), accurate (85.1-100.6%), and sensitive (LoD = 0.05-0.30ng/mg). The applied methods confirmed consumption of heroin in 18 subjects based on positive 6-acetylmorphine. Among these 18 heroin consumers, methadone was found in four, MDMA in two, and cocaine in two subjects. Cocaine only was present in two, methadone only in two, methamphetamine only in two, and MDMA only in seven of the 36 subjects. In two out of nine coloured and bleached hair samples, no drug was found. Despite the small number of subjects, this study has been able to indicate the trend in drug abuse among young people in Croatia.