A retrospective study was done of 73 consecutive Jehovah's Witness children less than 2 years of age who were operated on for lesions of the heart and major vessels. The series was divided into three groups: (1) neonates less than 31 days old, (2) children between 31 days and 2 years, and (3) children requiring cardiopulmonary bypass. The overall mortality rate for the series was 12.3% (9/73). Only three of the nine deaths were complicated by blood loss and anemia. The mortality rate for Group I was 18.2% (2/11). Only one of the two deaths was partly attributable to anemia. The overall mortality rate for Group II was 14.9% (7/47). Only two of these seven deaths were complicated by anemia. No deaths occurred among the 15 patients in Group III. Bloodless prime hemodilution techniques were used in all patients. Based upon our data, we have concluded that cardiac surgery can be performed when indicated on children of Jehovah's Witnesses with acceptable mortality rates and relatively straightforward perioperative care.