This case illustrates extensive bilateral polymicrogyria with right-sided 'close lipped' schizencephaly, associated with septum pellucidum absence and optic chiasm abnormality suggests co-existent septo-optic dysplasia, frequently associated with schizencephaly. Of interest, in cases of schizencephaly the degree of optic involvement in septo-optic dysplasia is less severe than when septo-optic dysplasia is found in isolation.