Ninety-nine patients with advanced epidemic Kaposi's sarcoma were treated with bleomycin-containing regimens: 30 received bleomycin and vincristine (BV) and 69 received doxorubicin, bleomycin, and vincristine. Treatment regimens were well tolerated, with response rates ranging from 76% to 81%. However, neutropenia developed even with the relatively nonmyelotoxic BV regimen. Twenty-eight of the 99 patients (28%) were evaluated for pulmonary function prior to, during, and after completion of combination chemotherapy to assess pulmonary toxicity commonly associated with bleomycin. The carbon monoxide diffusion capacity (DLCO) was the only measurement that showed significant changes prior to and after completion of therapy (P = .0003). Moreover, patients receiving more than 100 cumulative units of bleomycin experienced significantly greater declines in DLCO measurements than those receiving lower cumulative doses (P = .0067). No patient, however, developed clinically significant pulmonary toxicity attributable to bleomycin, with individual cumulative bleomycin doses ranging from 10 to 313 U (median, 112 U). We conclude that bleomycin is active and safe in the treatment of Kaposi's sarcoma, and close monitoring of pulmonary function is warranted with cumulative doses exceeding 100 U.