PURPOSE: Aplasia Cutis Congenita(ACC) is a rare disease characterized by the focal defect of the skin at birth, frequently involving scalp, but it may affect any region of the body. There are no etiology known but some conditions such as intrauterine vascular ischemia, amniotic adherences and viral infections are associated. The ideal treatment for the ACC is not known. Superficial and relatively small sized defects(<3x5cm) may heal spontaneously and large defects related with risks of infection and bleeding may require aggressive surgical treatment. Hyalomatrix(R) is a bilayer of an esterified hyaluronan scaffold beneath a silicone membrane. It has been used as a temporary dermal substitute to cover deep thickness skin defect and has physiological functions derive from the structural role in extracellular matrix and interaction with cell surface receptor. This material has been used for the wound bed pre-treatment for skin graft to follow and especially in uncooperative patient, like a newborn, this could be a efficient and aseptic way of promoting granulation without daily irritative wound care. For this reason, using Hyalomatrix(R) for the treatment of ACC was preferred in this paper. METHODS: We report a case of a newborn with ACC of the vertex scalp and non-ossified partial skull defect. The large sized skin and skull defect(6x6cm) was found with intact dura mater. No other complications such as bleeding or abnormal neurologic sign were accompanied. Escharectomy was performed and Hyalomatrix(R) was applied for the protection and the induction of acute wound healing for 3 months before the split-thickness skin graft. During the 3 months period, the dressing was renewed in aseptic technique for every 3 weeks. The skin graft was achieved on the healthy granulation bed. RESULTS: The operative procedure was uneventful without necessity of blood transfusion. Postoperative physical examination revealed no additional abnormalities. Regular wound management was performed in out-patient clinic and the grafted skin was taken completely. No other problems developed during follow-up. CONCLUSION: Hyalomatrix(R) provides protective and favorable environment for wound healing. The combination of the use of Hyalomatrix(R) and the skin graft will be a good alternative for the ACC patients with relatively large defect on vertex.