Massive hemoptysis is a life-threatening complication of many pulmonary disorders, and it occurs most com monly in association with longstanding inactive tuber culosis, bronchiectasis, lung abscess, bronchogenic car cinoma, and fungal disease. It is generally a neovascular change or local erosive effect of chronic pulmonary dis ease and may originate from either bronchial or pulmo nary circulation. Recurrent bleeding is unpredictable; therefore, diagnostic and therapeutic intervention must be undertaken with urgency. The immediate priorities must be protection of the airway to the nonbleeding lung and localization of the site of hemorrhage prefera bly by bronchoscopy, which has a high yield when per formed during active hemorrhage. Immediate control of bleeding may be obtained by local tamponade with a balloon-tipped Fogarty catheter, use of a double-lumen endotracheal tube, or angiographically guided emboliza tion. Surgical resection is the preferred definitive treat ment for those who meet operative criteria; those who lack adequate pulmonary reserve are candidates for em bolization of sites with persistent bleeding. The high mortality of conservatively treated massive hemoptysis and the current inability to predict which patients will have fatal hemorrhage mandate rapid assessment and intervention.