During a 10-year period from 1974 to 1984,19 patients at M. D. Anderson Hospital and Tumor Institute in Houston had invasive infection due to Trichosporon beigelii. Infection was manifested as either a nonspecific febrile illness or pneumonia, and the diagnosis was not suspected before death in 25% of the patients. The majority were neutropenic at the onset of infection, and recovery was directly related to resolution of myelosuppres- sion. The overall mortality rate was 74%. The majority of patients had polymicrobial infections. Twenty-four additional cases reported in the medical literature indicate that this pathogen is an increasingly important cause of mortality in immunosuppressed patients. In both the present series and the cases reported in the literature, the majority of neutropenic patients with disseminated T. beigelii infection died, despite antifungal therapy. Only those patients whose neutropenia resolved following remission of their leukemia recovered.