OBJECTIVE The results of primary bone grafting in terms of initial cleft width, existence or absence of a lateral incisor and scar formation in the donor area are compared. METHODS After primary osteoplasty with calvarian bone at an average age of 24 months (4-56 months) radiographic assessment was carried out in 31 patients with 40 alveolar clefts. The bone formation in the grafted area was assessed using dental radiographs taken at 66 months on average (13-114 months) after primary bone grafting. According to the Abyholm classification patients were assigned to 4 groups (indices I-IV) with indices I and II being rated as a success. RESULTS We observed success (indices I and II) in 76% and poor results (index IV) in 14%. The causes for the poor results were an alveolar cleft width of 11-12 mm in three cases, an extraction of a decayed deciduous tooth 17 months after bone grafting in one case and a traumatic transplant loss in another case. The non-existence of a lateral incisor and a broad cleft are related to poor results. CONCLUSIONS Based on the results presented, primary bone grafting using calvarial bone seems to be a promising alternative in bridging narrow alveolar defects. This method allows early intervention at an age in which children do not recognize themselves as cleft patients. The preservation of the deciduous teeth is equally important regarding their functional stimulus for bone development.