Aplasia cutis is a rare skin defect usually presenting over the vertex of the skull. An underlying bone defect is found in approximately 20% of patients. Most skull defects close spontaneously. However, when there are no signs of ossification, closure is mandatory. We present our experience in three patients. Our first patient had an aplasia cutis with a skull defect. The split rib graft procedure was used without complications, and a good cosmetic and functional result was achieved. The second patient was operated on for cerebral bleeding after an arteriovenous aneurysm, and a bony defect could not be closed after that procedure. At a later stage, the defect was filled with split rib grafts, and sufficient protection was achieved and documented after more than 30 years. The third patient was born with an aplasia cutis congenita with a skull defect. The bony defect was filled with split rib grafts without complications at an age of 5 years. Follow-up shows a functional result with a firm skull. Patients with aplasia cutis may have skull defects that will not close by themselves. We present three patients with a bony defect who were reconstructed with split rib grafts. After a long period of follow-up, there remains good cosmetic and functional results. Defects of the skull in children can be reconstructed with split rib grafts that will accommodate the growing skeleton and give good protection of the brain from an early age on.