This article reports a longitudinal study of developing communication in two profoundly deaf preschool boys growing up in oral deaf families who use oral English as their primary language. The children were videotaped in play interactions with their profoundly deaf mothers. The nature of the gestural communication used by the dyads is the focus of interest in this article. In contrast to hearing mothers of deaf children, the two mothers used extensive gestures to accompany their speech, including rich and varied gesture sequences. The children also developed a repertoire of gestures that, in most respects, mirrored the properties of the input gesture they received. The results provide a window on the natural ontogenesis of a compensatory gestural system.