A prospective study including 265 patient admissions for acute self poisoning are presented. Information on drug intake was obtained on admission. This was compared with the results from an extensive toxicological screening of blood samples drawn on admission and other information obtained later during hospitalization. The drugs used were identified clinically by the case histories and by routine laboratory analyses in 86% of the patients. In 14% either wrong drugs were suspected or the drugs were unknown. Extensive toxicological screening was needed to identify the drugs in 5% of the patients. Correct identification on admission did not seem to influence the clinical outcome. It is concluded that in this group of patients, it is possible to get reliable information concerning the drugs used by the case histories, clinical examination and routine laboratory analyses on admission.