Of 128 patients receiving primary treatment for molar pregnancy at Women's Hospital, Los Angeles County/University of Southern California Medical Center, after uterine evacuation 12 (10.7%) developed self-limited, acute pulmonary complications characterized by tachycardia, tachypnea, and hypoxemia. Multiple contributing factors have been identified which include trophoblastic deportation, hyperthyroidism, fluid overload, dilutional anemia, and pre-eclampsia. While the final outcome was uniformly benign in our group, deaths have been reported. These patients are also at an increased risk for postmolar trophoblastic disease. The diagnosis and management of the postmolar pulmonary complications are discussed.