We assessed intelligence and receptive and expressive language skills in 6 children, ages 7 years 9 months to 12 years 4 months, with bilateral perisylvian polymicrogyria of variable extent and with dysarthria of different severity. In view of the recent findings of a close relationship between word and gesture, we also examined the communicative use of gesture. We found that mental retardation was related to the extent of cortical malformation; lexical comprehension, but not morphosyntactic comprehension, and verbal production were more compromised than expected from nonverbal intellectual abilities; lack of verbal language was not compensated by the use of referential gestures. Results are discussed suggesting that compromised verbal and gestural communication in bilateral perisylvian polymicrogyria are not due simply to mental retardation and/or dysarthria but also to dysfunction of Sylvian fissure areas concerned with the totality of language processing.