A patient receiving continuous ambulatory peritoneal dialysis, and who was known to be seropositive for human immunodeficiency virus but without AIDS or ARC, had peritonitis secondary to Trichosporon beigelii. The patient had been receiving oral antibiotics and had had recurrent bouts of bacterial peritonitis. Infection was cured with removal of the peritoneal catheter and intraperitoneal and intravenous amphotericin B. The course of this episode of Trichosporon beigelii peritonitis was similar to that of peritonitis caused by other yeasts.