Ten cases of cryptococcosis have been identified in a 13 year experience with more than 650 renal transplants. Eight patients had meningitis, one patient had a cerebral granuloma, and in one patient the infection appeared to be limited to the lungs. The central nervous system infection often masqueraded as brain tumor and was not suspected initially. The most useful diagnostic test was cerebrospinal fluid examination including India ink preparation. Various ther apeutic regimens with amphotericin B and 5-fluorocytosine were effective in suppressing the infection. A combination of low doses of amphotericin B, not affecting kidney function, with 5-fluorocytosine for at least 3 months was associated with remission of disease in five patients who still are alive, including three patients without recurrence for longer than one year. Five deaths 3 weeks to 4 years after the beginning of treatment were not due to cryptococcosis; death resulted from vascular disease and septiciemia in three of the four patients with known causes of death. Central nervous system cryptococcosis, with the exception of the rare cerebral granuloma, is associated with little inflammation. If early death from increased intracranial pressure or cerebral edema is prevented, prolonged therapy with amphotericin B and 5-fluorocytosine may be expected to control the infection, even in immunosuppressed patients.