Sixty-one critically ill infants with congenital heart disease had operative treatment within 6 weeks of birth. Anatomic and physiologic diagnoses were established preoperatively by cardiac catheterization and angiography in all. A variety of palliative or corrective operations was performed to relieve specific hemodynamic burdens. Thirty-seven (61%) survived hospitalization, but 18 had one or more postoperative complications. At the present time, 29 (48%) are alive 9-45 months after operation. Although operative mortality and morbidity rates are high, none of these patients was expected to survive early infancy without operation.