In 4 infants, 3 boys and 1 girl, the congenital absence of skull skin was diagnosed: aplasia cutis congenita, a rare congenital skin defect, which usually presents as a solitary defect over the vertex of the skull measuring a few to approximately 10 centimetres. All four patients were treated with a skin transplantation and more than a year later the skin covered the skull well. There is no consensus concerning the treatment of aplasia cutis congenita. Due to unfamiliarity with this condition, a conservative approach is often adopted. The management strategy indicated should depend on the size of the defect and the child's physical condition. In the case of large defects, an early operative treatment is desirable to prevent serious complications such as haemorrhages and infections. Sufficient skin coverage can be obtained by using rotation scalp flaps, and if necessary additional split-skin grafts. In some patients large rotation flaps are not reliable due to the abnormal vascularity of the skin (Adams-Oliver syndrome). Split-skin grafting is the treatment of choice in these patients.