Two patients suffering from seizures unresponsive to medical treatment underwent two-stage "central" commissurotomy. In one patient anterior callostomy was carried out first; in the other the surgical procedure was performed in the reverse order. The clinical, EEG, and neuropsychological features of the two patients are reported before the operation, between stage 1 and stage 2 of the procedure, and after completion of the commissurotomy. The surgical aspects of the two different procedures and the related clinical pictures are described in detail.