Maxillary morphology and dental occlusion were studied from infancy to age 10 years in 32 patients born with isolated cleft palate. Wardill-Kilner push back repair of the palate had been done at a mean age of 7.5 months. Measurements obtained from casts of the jaws showed that the average maxillary dimensions before as well as after operation were less than those reported for children without clefts. The mean reduction was similar whether the cleft reached into the hard palate or affected the soft palate only. Preoperative anterior maxillary arch width in particular, and also distance from scar line to selected teeth seemed to influence postoperative development of the maxillary dental arch in individual patients.