This review examines research on intelligence, achievement, behavior, and personality of children with cleft lip and palate. Studies of intellectual functioning indicate that the general intelligence of cleft samples is relatively normally distributed with group mean IQ scores within the Average range. There is some suggestion of a higher frequency of depressed verbal intellectual functioning relative to visual-motor intelligence. Factors that appear to affect IQ levels are presence of other congenital anomalies, speech and hearing deficiency, and low incidence cleft-type by sex occurrences. There is evidence that a high percentage of cleft children are underachievers. Personality and behavioral studies do not suggest significant psychopathology, although there is evidence of behavioral inhibition, concern regarding appearance, and decreased expectations by teachers and parents.