Cognitive deficits have been well-documented in children with non-syndromic clefts of the lip and/or palate. However, no study to date has formally assessed cognition in adults with oral clefts. This study was designed to evaluate neuropsychological functioning in adult males with non-syndromic clefts of the lip and/or palate (n=50) compared to age and sex-matched controls. Subjects with oral clefts were found to have significantly lower full scale IQ, performance IQ and verbal IQ scores compared to their matched controls. After controlling for IQ, patients showed specific deficits in verbal fluency. Adult males with oral clefts manifest a specific pattern of cognitive deficits. As the development of the face is highly interdependent with the development of the brain, it is theorized that the etiology of these cognitive deficits is a primary problem with abnormal brain development.