In the present study, a modified dictator game was used to test the hypothesis that the threat of gossip would encourage prosocial decision making. All participants were asked to distribute an endowment between themselves and an anonymous second party. Half of the participants were told that the second party would be discussing their economic decision with a third party. For some participants, this third party was someone to whom they had first disclosed personally identifying information. Participants who received the threat of gossip manipulation were more generous than control participants, but only when the third party could personally identify them was this difference significant. These data reveal that at least some prosocial decisions are motivated by actor's reputational concerns—concerns that are directly mediated by language.