Introduction: Aplasia cutis congenita is a rare congenital absence of skin most commonly affecting the scalp. Although most defects are small and superficial, approximately 20% of cases involve absence of the skull. Such defects expose the brain and sagital sinus, with concomitant risk of fatal hemorrage, infection, or both. This anomaly most commonly presents as a solitary defect, but sometimes it may occur as multiple lesions. The lesions are noninflammatory and well demarcated, and range is variable from 0.5 cm to 10 cm or more. Although the majority of these scalp defects occurs sporadically, many family cases have been reported. Multiple causes have been suggested for aplasia cutis: genetic causes, syndromes and teratogens, intrauterine infection -varicella zoster virus, herpes simplex virus-, fetal exposure to cocaine, heroin, alcohol or antithyroid drugs., Materials and Methods: A retrospective study of children with Aplasia Cutis Congenita who received treatment in Hospital La Paz, in Madrid between 1995 and 2005 was undertaken. We checked location, moment of the surgery, type of surgery and aesthetic results., Results: In the 20 year period between 1985-2005, we treated 36 patients with Aplasia Cutis. 33 of them have the scalp affected and only in 3 cases the trunk was involved. In 4 cases there was an absence of the skull, two slight and two severe. 3 patients had Adams-Oliver and one Cutis Marmorata Telangiectasica syndrome. Fifteen patients were operated in neonatal period with direct closure or advancement or rotational flaps, and in 17 cases the late treatment included use of tissue expanders to cover definitely the defect. One of the patients died for bleeding of the sagital sinus while was waiting for the secondary closure of the wound, and other patient required complex skull reconstruction to achieve a complete coverage., Conclusions: In view of our experience and results, we believe that early surgery prevents vital risks, reduces local complications and makes easier the final reconstruction.