AORTIC valvular atresia with hypoplastic aortic arch is one of the most common cardiac lesions causing heart failure and death in the first few days of life.1,2 Although this lesion is thought to be sporadic, the occurrence of aortic atresia in siblings is most unusual. The only similar case was presented by Brekke3 in which one sibling had aortic valvular atresia, and the other, hypoplasia of the aortic valve. It is the purpose of this paper to discuss the occurrence of aortic atresia in two siblings. Report of Cases Case 1.—A male infant was the product of a full term pregnancy born to a 27-year-old white female primigravida. The pregnancy and delivery were normal. The apgar score at one minute was 9. The infant did well for the first three hours of age when minimal cyanosis became evident. Examination at this time was considered to be within normal