Aplasia cutis congenita is an uncommon condition; fewer than 300 cases have been reported in the literature. Usually, the condition occurs as a focal scalp ulcer, but it may involve the full thickness of the skull or other areas of the body. Most lesions require coverage with a scalp flap, though only observation or split-thickness skin grafts may be adequate for smaller lesions. Four cases have been presented, representing a spectrum of therapeutic requirements from simple observation to emergency intervention to control life-threatening hemorrhage. The case of aplasia cutis congenita of the upper arm may represent a persistence of prenatal focal ischemia that has proved to be resistant to numerous attempts of split-thickness skin grafting.