A woman presented with polyhydramnios when 33 weeks pregnant, and three weeks later delivered an infant with idiopathic non-immune hydrops fetalis. Ultrasonic scanning before birth showed a severely edematous infant. An abdominal radiograph revealed the classical "Buddha" position of fetal hydrops. The cause of the infant's hypoalbuminemia could not be determined, but the infant responded quickly to intravenous albumin and to thoracentesis for the large pleural effusions. As non-immune hydrops becomes proportionately more common, radiologists should be aware that the diagnosis of "hydrops fetalis" is not synonymous with "erythroblastosis."