The epidemiology of 737 consecutive self-poisoning admissions to Freeman Hospital, Newcastle upon Tyne, has been investigated with reference to age in young (less than 35), mid-aged (35-64) and elderly (greater than or equal to 65 year) patients. The most important differences were increased formal psychiatric illness in the elderly, demonstrated by increased likelihood of admission to psychiatric units; less likelihood of overdose with multiple agents in the elderly, and less use of alcohol. There were also differences in the types of drugs used. The youngest patients took more paracetamol and less psychoactive drugs and more of their drugs were prescribed for a relative than the other two groups. The elderly were much less likely to receive gastric lavage or emesis and more likely to receive supportive treatment only than younger patients. This difference may, in part, be explained by the more frequent occurrence of benzodiazepine poisoning in those over 65 years.