Between 1993 and 2000, 30 infants were hospitalized with acute pulmonary hemorrhage at Rainbow Babies and Children's Hospital in Cleveland. Most infants presented with severe pulmonary symptoms requiring intensive support, but a few infants had less severe hemorrhage. Three quarters of the patients required ventilator support and blood transfusions. Eleven patients had transitory hemoglobinuria. Five patients died, but infants who survived did well. There are currently no specific treatment modalities, although we have advised moving to a different home and avoiding environmental tobacco smoke. Subsequently, rebleeding from the lower respiratory tract has decreased from 5 of 7 infants to 1 in 21. On the basis of decreased subsequent fatal hemorrhage, high dose glucocorticoids seem to be of some value. Several patients revealed continued low-grade alveolar hemorrhage for months after their initial bleed, even after removal from their original home environments.