A laboratory study was carried out to establish the relative importance of verbal and gestural behavior, as well as their interaction, for perceived social influence in more or less competitive small groups. Forty women (psychology students) participated in leaderless small group discussions of different sizes (four-member and eight-member): at the end, each member rated the perceived influence in decision-making of every other member. Verbal dominance coding is based on traditional quantitative conversational dominance (number of talk turns). Gestural coding (conversational, ideational, object-adaptor, self-adaptor gestures) is based on classical gesture classifications. Beside a substantial effect of verbal dominance, the main result is that frequency of object-adaptors and conversational (only in large groups) and ideational (in both small and large groups) gestures increases perceived influence scores particularly when the verbal dominance of the speaker is low.