In the period 1987-1991 a total of 739 fatalities among drug addicts was investigated at the three University Institutes of Forensic Medicine in Denmark. The annual number rose from 130-140 in the first 4 years to 192 in 1991, and 80% were males. The mean and median age for both males and females increased by 1 year in the period. The main drug of abuse was heroin, in most cases supplemented by various other drugs, and in almost all cases taken intravenously. In about one-third of the cases each year there was information of abuse of alcohol in addition. In the poisoning cases, the main drug of poisoning was morphine/heroin, constituting 35-55% of the cases each year. As regards methadone-poisoning cases, the number increased significantly in 1991 compared to the first 4 years. Furthermore, the number and proportion of addicts dying while in methadone treatment increased during the 5-year period. In about half of the methadone poisoning cases, there was information of methadone treatment at the time of death. The other half obviously obtained the methadone completely illegally. Ketobemidone was the third most frequent drug of poisoning, while propoxyphene and barbituric acid only were found in a very few cases each. The results are compared to those from an earlier investigation concerning drug deaths in Denmark in 1968-1986. The importance of registering drug deaths is emphasized.