Sulfamethoxazole-trimethoprim may be an alternative or adjunctive treatment for Wegener's granulomatosis, as suggested by our experience with six patients. Two had limited Wegener's granulomatosis; one of these achieved remission with sulfamethoxazole-trimethoprim alone, and the second achieved remission with sulfamethoxazole-trimethoprim and prednisone. Four patients presented with sinus, pulmonary, and renal involvement. One patient initially treated with sulfamethoxazole-trimethoprim developed worsening renal function requiring cytotoxic therapy. Two patients initially treated with cytotoxic agents achieved remission coincident with the addition of sulfamethoxazole-trimethoprim for persistent sinus symptoms. One patient had relapse of pulmonary symptoms after achieving and maintaining a remission during treatment with sulfamethoxazole-trimethoprim alone. This experience suggests that sulfamethoxazole-trimethoprim may be an effective treatment for some patients with Wegener's granulomatosis and may be the only agent required. Patients require careful follow-up and still may need cytotoxic therapy.