This is a prospective study on the pattern & complications of deliberate self-poisoning among diabetic patients referred to the National Poisons Information Service, London, during the years 1978 & 1979. Of 386 cases of overdosage in diabetics, 18 involved deliberate overdosage of insulin. The majority of patients however took a range of non-diabetic drugs & in only 24 cases was multiple overdosage reported. Possibility of deliberate overdose should always be considered in a comatose diabetic.LN