The effect of primary bone grafts on craniofacial growth was evaluated in adult patients with complete unilateral cleft lip and palate (UCLP). The subjects were 18 UCLP patients with primary bone grafts and a control group of 36 UCLP patients without bone grafts. The former received primary transplantation of autogenous rib bone simultaneously with primary cheiloplasty by the same surgeon between 1963 and 1969. Frontal and lateral cephalograms taken after 16 years of age were traced. Skeletal landmarks were identified on them, and their x,y-coordinates were digitized. The effects of gender and/or primary bone graft on the craniofacial morphology were tested by ANOVA using 21 angles, 8 breadths, 13 distances, and 2 ratios. Nasal cavity breadth was wider in the primary bone grafted group. However, the anterior maxilla in that group was more upward and retruded than that in the nongrafted group. The primary bone grafted group was divided into two subgroups based on the overjet of the incisors: group N = normal overjet; group C = anterior cross-bite. There was no difference in the maxilla between groups N and C. However, the mandible in group C was more anterior and superior than in group N. In conclusion, primary bone graft may impede maxillary horizontal and vertical growth to a certain degree, and severe anterior cross-bite in primary bone grafted subjects may be brought about by mandibular closure.