This article tests the effect of accountability on negotiation outcomes in a face-to-face classroom experiment. Student participants were asked to form coalitions in groups of three. In the treatment condition, negotiators were held accountable by a personal forum during the formation of the coalition. In the control condition, negotiators were not held accountable. Results show that accountability leads to lower group performance in coalition negotiations. Accountability also reduced the willingness of negotiators to include all negotiators in a “grand coalition.” Rather, accountable negotiators reached agreement with a subset of negotiators. Accountability increased the odds of reaching no agreement. These findings challenge the idea of increased performance as a result of public accountability in the context of coalition negotiations.