Landau—Kleffner syndrome (LKS) is an acquired epileptic aphasia occurring in childhood and associated with a generally poor prognosis for recovery of speech. It is thought to be the result of an epileptogenic lesion arising in speech cortex during a critical period of development. Utilizing a new surgical technique designed to eliminate the capacity of cortical tissue to generate seizures while preserving the normal cortical physiological function, we have treated 14 children with aphasia, seizures and a severely abnormal EEG by multiple subpial transection of the epileptogenic cortex. Seven of the 14 patients (50%) have recovered age-appropriate speech, are in regular classes in school and no longer require speech therapy. Four of the 14 (29%) have shown marked improvement, are speaking and understanding verbal instruction but are still receiving speech therapy. Thus, 11 of the 14(79%), none of whom had used language to communicate for at least 2 years, are now speaking—a rate of sustained improvement considered unusual in this disorder. This study documents the value of a treatment modality not previously used in LKS. Success depends on selection of cases having severe epileptogenic abnormality that can be demonstrated to be unilateral in origin despite a bilateral electrographic manifestation