Scholars recognize that planning is an essential part of negotiation, but research provides limited insight into the nature of effective negotiation planning. This research is focused on the skills necessary for effective negotiation planning. It is argued that the information processing tendencies of high self-monitors make them particularly adept at planning for negotiations. The authors extend existing work in planning by relating self-monitoring to plan generation, plan enactment, and plan consequences. Results indicate that self-monitoring is related to prenegotiation goal commitment, planning of impression management strategies, planning of integrative tactics, and plan complexity. During negotiations, high self-monitors are more likely to engage in argumentation. However, they are not especially inclined to engage in more information seeking or rapport building. High self-monitors are better able to accomplish negotiation goals, and this appears to be the result of their superior planning skills. Results have implications for plan-based theorizing and for practicing negotiators.