Pulmonary mucormycosis is relatively uncommon but an important opportunistic fungal infection in immunocompromised persons. The literature on the subject is sparse. We describe a recent case and review the literature to delineate the clinical characteristics of this infection. We searched the MEDLINE database for articles published in the English-language literature since 1970 and carefully analyzed 87 cases. The main risk factors were diabetes mellitus, hematologic cancers, renal insufficiency, and organ transplantation. Several patients had no apparent immune compromise. There was a predilection for involvement of the upper lobes. Air crescent signs on chest x-ray films were predictors of pulmonary hemorrhage and death from hemoptysis. Fiberoptic bronchoscopy was a useful diagnostic method, and histopathologic examination was more sensitive than fungal cultures. The overall survival rate was 44%. Patients treated with a combined medical-surgical approach had a better outcome than patients who did not undergo surgery. Thus, this relatively rare but often fatal disease should be suspected in immunocompromised patients who fail to respond to antibacterial therapy. Early recognition and aggressive management are warranted to maximize chances for cure. Optimal therapy requires systemic antifungal therapy, surgical resection, and, when possible, control of the patient's underlying disease.