This investigation examined psychopathology and IQ levels in 30 children with CSWS and 42 children with BRE and compared them with 40 healthy controls and 23 children with absence epilepsy by using the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS) and Wechsler Intelligence Test for Children (WISC-R). The CSWS and BRE groups had the highest rate of psychiatric diagnoses and lowest IQ scores. The BRE group had higher rates of psychopathology and lower IQ scores compared to the healthy controls. While BRE and absence groups did not differ with regard to presence of psychopathology, IQ levels and types of psychopathologies, children with CSWS had more psychiatric disorders and lower IQ scores compared to the patient group with absence epilepsy. These findings suggest that CSWS and BRE are two epileptic syndromes that lead to psychiatric disorders and lower IQ scores. Hence, psychiatric consultation should be a part of the treatment while managing these children.