Abstract Mucormycosis is a rare opportunistic infection that complicates chronic debilitating diseases and immunosuppressed solid-organ transplant recipients. We present a case of life-threatening pulmonary mucormycosis in a diabetic renal allograft recipient who survived with reasonable renal function. Early recognition of this entity and prompt use of bronchoalveolar lavage (BAL) are critical to the outcome. Antifungal therapy combined with early surgical excision of infected, necrotic tissue appears to be the preferred course of action. Judicious withholding of immunosuppressants until fungemia cleared did not jeopardize allograft function. © 2001 by the National Kidney Foundation, Inc.