Forty-one homosexual men with the acquired immune deficiency syndrome (AIDS) or AIDS-related complex were treated with 0.5, 1.0, or 1.5 g of suramin weekly for up to six months. In no patient was evidence of symptomatic improvement or regression of Kaposi's sarcoma shown. Opportunistic infections developed in 16 patients during therapy. Only six patients (15 percent) became human immunodeficiency virus (HIV) culture-negative during treatment, despite documentation of adequate serum suramin levels. All but one of these six have had disease progression. Decreases in the numbers of total T4 cells with time were observed in both AIDS and AIDS-related complex subgroups. Toxicity was significant and consisted of fatigue, fever, and hepatic and renal dysfunction, all of which were observed most frequently with the 1.0 or 1.5 g dosages. Fatal hepatic failure developed in two patients, and adrenal insufficiency was documented in eight patients. Suramin is a toxic agent that shows no virologic, immunologic, or clinical benefit in patients with HIV-related disease.