Four (possibly five) boys are described with a profound comprehension deficit for acoustic language, leading to severe or complete abolition of expressive speech. One boy had presumed megalencephaly from birth but was of superior intelligence. He had a severe articulation deficit from early childhood, with delayed acquisition of speech. Another boy is thought to have a small angiomatous anomaly in the depth of the left parietal lobe. No brain lesions are known in the other three. Evidence for bilateral brain dysfunction consists of minor motor abnormalities in three boys, oromotor deficits in two boys, and bilaterally synchronous diffuse or independent focal paroxysmal discharges in the EEG of three, possibly four, of the boys. Seizures have occurred in only three boys, and have been easily controlled with anticonvulsants. One boy with a grossly abnormal EEG has had no clinical seizures to date and has not benefited frome one year of anticonvulsant therapy. Two of the boys are brothers, including the boy in whome the diagnosis is questionable since speech was never normal and since he has had neither seizures for an abnormal EEG. The severity of EEG abnormalities did not correlate closely with the course of the language deficit. The relationship of this syndrome to acquired aphasia in children, to Wernicke's aphasia and pure word deafness in adults, and to developmental lagnuage disability with predominantly receptive deficits, is discussed. One child illustrated the close association between writing and phonologic encoding and decoding operations, and two children the preservation of linguistic skills provided the acoustic channel was by-passed and language presented visually. This latter point has been emphasized because of its implications for the remedial education of children with this syndrome.