During the period 1988-1991 HIV-1-antibody tests were performed on a total of 389 autopsied drug addicts. The HIV-1-incidence rose from 6 per cent in 1988 to 14 per cent in 1990 and 14 per cent in 1991. There was no significant difference between the cumulated incidence in males and females. The HIV-1-positive addicts were compared to the HIV-1-negative addicts with respect to mean age, duration of abuse, residence and cause and manner of death. Except for residence, where significantly more HIV-1-positive than negative addicts lived in Copenhagen, there were no significant differences between the two groups. In about one third of the HIV-1-positive cases, equally for males and females, the HIV-1-positivity was not previously known. The results are discussed in relation to the findings in other countries and to the findings in selected groups of living addicts in Copenhagen. It is concluded that the diagnosis of HIV-1-infection in autopsied drug addicts is important from epidemiological and hygienic points of view.