Morphine and methamphetamine, which are excreted in the sweat, are detected by the use of routine serological and physicochemical techniques for urinary examinations. Screening for drug abuse can be done with the same accuracy of that of urine. Rapid excretion of the drug via kidney (within one day) is followed by a slow but steady excretion of the sweat gland. Methamphetamine given orally in a dose of 10 mg is excreted in the sweat at a constant rate (1.4 microgram/ml). No significant difference of the amount excreted by both systems is found. Alveolar lining seems to prevent the elimination of the volatile methamphetamine via respiration. Not only narcotics and stimulants, but also many alkaloids and barbituarates are excreted in the sweat and detected quantitatively by the same principles. The toxicological analysis of the sweat promises a new scope of forensic investigation.