CMV disease is an important cause of morbidity and mortality in patients with AIDS. The purpose of this study was to investigate the incidence of CMV disease in a well-defined population of AIDS patients with a high rate of autopsy. No such study has previously been published from Scandinavia. A total of 248 patients who developed clinical AIDS in Oslo during the period 1 January, 1983 to 31 December, 1995 were included. Autopsy was performed in 152 of 213 deaths (71.3%). CMV disease was diagnosed in 95 patients. In the autopsy group, 73 patients (48%) had CMV disease, and in 52 of these patients CMV disease was first detected at autopsy. Retinitis was the most frequent manifestation, followed by adrenalitis, pneumonitis, encephalitis and gastrointestinal disease. No intravenous drug users (IVDUs) were diagnosed alive with CMV disease. All patients diagnosed with CMV disease before death had evidence of CMV disease at autopsy despite anti-CMV treatment. CMV disease was associated with increased risk of death. We conclude that CMV disease was frequent in patients with AIDS during the study period, was associated with increased mortality and was often diagnosed too late for the administration of appropriate therapy.