Secondary bone grafting of a residual alveolar cleft has become a well established procedure. However, little attention has been paid to the benefits of these bone grafts in patients with clefts of the lip and alveolus only. This retrospective and comparative study includes 21 patients who had received a secondary or a late secondary bone grafting procedure from tibia and whose mean clinical and radiographic follow-up after the bone graft was 5.5 years. Eighteen patients treated without bone grafting served as controls. Length and width of cleft, presence or absence of permanent lateral incisor, size of nasal floor bony defect, and interdental alveolar bony height in the cleft area were investigated. The results showed that bone grafting was indicated particularly in wide clefts with missing lateral incisors. Eruption of a tooth close to the cleft was facilitated and the bony support for teeth neighboring the cleft was improved. In some cases, additional support of the alar base of the nose was achieved and closure of an oronasal fistula facilitated. A further advantage of bone grafting of clefts of the primary palate was that it might make it possible to insert a titanium implant carrying an artificial tooth in the cleft area.