This study investigates the effect of conflict resolution methods on the IS outsourcing performance. A survey of 207 IS outsourcing relationships of U.S. firms indicates that (1) constructive/proactive methods, such as joint problem solving, is positively related to the success of IS outsourcing relationships, and that (2) destructive/passive methods, such as persuasion, smoothing/avoiding, domination, and use of harsh words are negatively related to the success of IS outsourcing relationships. The findings suggest that the manner in which conflict is resolved can be productive or destructive for the IS outsourcing performance.