This study was designed to test the influence of simultaneous cleft lip and palate repair on facial growth in rabbits. Three groups of rabbits were used. Group I consisted of control rabbits who had no surgery; Group II had surgically created, but unrepaired, clefts of the lip, alveolus, and palate; and Group III had surgically created clefts of the lip, alveolus, and palate followed by immediate simultaneous lip and palate repair. In Group III, the lip was repaired using the Millare technique and the palate using two-flap palatoplasty, leaving no bare bone exposed. All animals were sacrificed after twenty weeks. Results of the direct cephalometry of the skulls confirmed that simultaneous lip and palate repair results in inhibition of anterior-posterior and transverse maxillary growth. Some significant changes were also found in mandibular length and nasal deflection. All 15 rabbits with simultaneous cleft lip and palate repair developed anterior crossbites and functional shifts to the left or cleft side. Further analysis comparing the results of facial growth inhibition in this study with inhibition following lip repair only or palate repair only will be necessary to assess the severity of secondary maxillo-facial deformities resulting from lip and palate repair.