The records of 187 consecutive patients with acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma were analyzed retrospectively for a number of prognostic variables. In a multivariate analysis, the initial site of disease was found to be related to survival. Initial lesions on the skin of the lower extremities or in the lymph nodes were associated with longer survival (p = 0.005 and p = 0.01, respectively). Higher helper/suppressor T cell ratios were strongly associated with longer survival (p less than 0.0001). Age and serum IgG antibody levels to cytomegalovirus did not appear to correlate. These results suggest that there are different subgroups of patients with AIDS-associated Kaposi's sarcoma, and that the initial site of disease, as well as immunologic parameters, may be useful in prognosis.