Pulmonary hemorrhage is a serious complication in very-low-birth-weight (VLBW) infants with respiratory distress syndrome (RDS). We undertook a 2-year retrospective study to investigate the predisposing factors and the incidence of pulmonary hemorrhage in VLBW infants. From January 1997 through December 1998, twenty infants were diagnosed with massive pulmonary hemorrhage (MPH) according to the following criteria: active bleeding from the endotracheal tube, acute drop in hematocrit (?10%), and the development of multilobar infiltration on chest radiograph. The mean gestational age was 26.9 ? 2.5 weeks, the mean birth weight was 909 ? 290 g. Twenty historic controls with similar gestational age and birth weight were retrospectively identified during the study period. The incidence of MPH in VLBW infants was 5.9%(20/340). A lack of prenatal corticosteroid administration, surfactant replacement therapy for RDS, and a patent ductus arteriosus (PDA) with cardiovascular dysfunction requiring dopamine support were the significantly predisposing factors of MPH in the acute stage(? 7th day of life). To avoid MPH and decrease mortality and morbidity in the acute stage, prenatal corticosteroid administration, evaluation of the necessity of surfactant therapy, and early recognition and aggressive treatment of hemodynamically significant PDA were necessary.