The zygomycetes are saprophytic fungi that rarely cause disease in the normal human host. In immunocompromised individuals, these organisms can cause invasive infections, collectively called mucormycosis. Mucormycosis is associated with a high mortality rate, especially in organ transplant recipients. In this report, we describe the first case of successfully treated mucormycosis involving a pulmonary allograft. Treatment consisted of surgical excision of the affected lobe and chest wall and lipid-complex amphotericin B. The lipid complex formulation permitted a prolonged course of therapy that was likely critical to eradication of the infection. Copyright (C) 1999 International Society for Heart and Lung Transplantation.