The clinical and pathological findings in 46 patients with cryptococcosis at Memorial Sloan-Kettering Cancer Center from 1956 to 1972 are reported. The striking predilection for cryptococcal infection in patients with leukemias and lymphomas is again confirmed. Of 41 patients with neoplastic disease, those with chronic lymphatic leukemia (CLL), Hodgkin's Disease, chronic myelogenous leukemia (CML), myeloma and lymphosarcoma had the highest incidence of cryptococcosis. In all cases, neoplastic disease was widespread when infection occurred. All of these patients had leukopenia and absolute lymphopenia at the time of infection. Thirty-nine were on steroids. Thirty-one patients with neoplastic disease had disseminated infection. Review of pathology revealed a spectrum of inflammatory lesions. Histiocytic-lymphocytic infiltrates occurred in the central nervous system in 10 patients. In six cases, reaction was granulomatous. There were single instances of suppurative and fibrotic reactions. Mortality from infection was high in patients with neoplastic disease. Twenty-four of 28 deaths occurred within 60 days as a result of infection. Within one year, 10 more patients died, nine of cryptococcosis. Only three survived more than one year, and all patients died within 600 days. Twenty-nine patients with neoplastic disease received amphotericin B. Only nine survived more than 60 days.