During the years from 1977 to 1986, 21,410 specimens were collected for clinical drug screening from 13,589 patients. The specimens included 9,530 blood samples, 9,184 urine samples and 2,717 samples of gastric contents. One or more drugs/drug metabolites were detected in 74% of the specimens. Gastric contents were positive most often (85%) followed by urine (79%) and blood (66%). Although the 5 most frequently detected drugs did not change (caffeine, ethanol, nicotine, salicylates and acetaminophen), the presence of cocaine, phenylpropanolamine, diphenhydramine and the group of cyclic antidepressants steadily increased over the time period. Over 200 different drugs/drug metabolites were detected in the drug screens, contributing a significant amount of information for the appropriate diagnosis and treatment of the patients for which the testing was requested.