In 2 fetuses with congenital cystic adenomatoid malformation (CCAM) with hydrops, in-utero resection of the enlarged pulmonary lobe reduced mediastinal shift and allowed expansion of normal lung tissue in both cases. In case 1, the 27-week-gestation fetus died from severe hydrops after premature delivery. In case 2, fetal CCAM resection was completed at 23 weeks' gestation. At 30 weeks a girl was delivered with no evidence of pulmonary hypoplasia. Fetal surgery can now be entertained for otherwise fatal space-occupying intrathoracic lesions.