Fungal infections of prosthetic dialysis fistulae are rare. We report the first case of infection of a polytetrafluoroethylene dialysis access graft with the yeast Cryptococcus neoformans. Therapy with antifungal agents alone failed to cure the infection and significant improvement was observed only when all prosthetic material was surgically removed. This case emphasizes the potential for fungal infection of prosthetic dialysis fistulae and the importance of removal of intravascular foreign material in conjunction with antifungal therapy for treatment of fungal prosthetic graft infections. (C) 1994 by the National Kidney Foundation, Inc.