A total of 4200 intravenous drug users enrolled in methadone treatment centres between 1980-88 were studied to examine overall & cause-specific mortality. There were 239 deaths during the follow-up period. A large excess of mortality in both sexes was found for infectious, circulatory, respiratory & digestive diseases as well as for violence, overdose, AIDS & unknown causes. Tumors & suicide were excessive only in males. Findings document the serious health consequences of drug abuse in Italy.