SUMMARY: Driving under the influence of drugs is an issue of growing concern in the industrialized countries as a risk and a cause for road accidents. In forensic toxicology, the increasing number of samples for determination of drugs in blood is mainly due to zero-tolerance laws in several countries and well-trained police officers who can better recognize drivers under the influence of drugs of abuse. This review describes procedures for detection of the following drugs of abuse in whole blood, plasma, and serum: amphetamine, methamphetamine, 3,4- methylenedioxy methamphetamine (MDMA), N-ethyl-3, 4- methylenedioxyamphetamine (MDEA), 3,4-methylenedioxyamphetamine (MDA), cannabinoids (delta-9-tetrahydrocannabinol [THC], 11-hydroxy-delta-9- THC, 11-nor-9-carboxy-delta-9-THC), cocaine, benzoylecgonine, ecgonine methyl ester, cocaethylene, the opiates (heroin, 6-monoacetylmorphine, morphine, or codeine), and methadone as well as gamma-hydroxybutyric acid (GHB), lysergic acid diethylamide (LSD), phencyclidine (PCP), and psilocybin/psilocin. For many of the analytes, sensitive immunologic methods for screening are available. Gas chromatography-mass spectrometry (GC-MS) is still the state-of-the-art method for confirmatory analysis or for screening and confirmation in one step. Liquid chromatography-mass spectrometry (LC-MS) procedures for such purposes are also included in this review. Basic data about the biosample assayed, internal standard, workup, GC or LC column and mobile phase, detection mode, reference data, and validation data of each procedure are summarized in two tables.