We looked at survival of 138 patients with HIV-1-associated Kaposi's sarcoma. Patients with lesions of the oral mucosa had a higher death rate (risk ratio 3.4 [95% CI 1.6-7.1]; p=0.001) than those having exclusively cutaneous manifestations of the disease. Patients with oral Kaposi's sarcoma and a CD4 cell count of at least 150/microL had a similar mortality risk to patients with the cutaneous disease but CD4 cell concentration of no more than 150/microL. Thus, oral Kaposi's sarcoma is an important prognostic marker, at least for patients who do not receive triple antiretroviral therapy.