Sixty-three cases of Hodgkin's disease in intravenous drug users (IVDUs) have been collected by the Italian Cooperative Group on AIDS-Related Tumors (GICAT). In most patients (74%) the histological pattern was that of mixed cellularity and lymphocyte depletion. In 39% of patients the initial symptom was a persistent lymph node enlargement due to persistent generalized lymphadenopathy (PGL). Unusual presentations included Waldeyer's ring, skin, meninges, colon, and pleura. After MOPP alternated or followed by ABVD, MOPP alone, or ABVD alone, 15 of 32 patients (47%) had a complete remission (CR) and 15 of 32 (47%) had a partial remission (PR). The median duration of CR was 14 months, while the median survival of patients with CR has not been reached; the median survival of patients treated with chemotherapy who had CD4 levels at presentation greater than or equal to 400/mm3 was significantly superior to that of those who had CD4 less than 400/mm3. The overall median survival was only 14 months. Forty-four percent of patients receiving chemotherapy, with or without radiotherapy, developed opportunistic as well as nonopportunistic infections. Lethal hepatic toxicity was observed in one patient. Among IVDUs, unusual presentations of Hodgkin's disease occurred at a lower rate than was previously reported for homosexuals. Complete remissions could be achieved in almost half the patients, but non opportunistic infections, in addition to parenchymal function impairment due to drug abuse, may limit treatment administration in IVDUs.