Previous research has failed to demonstrate a consistent relationship between a leader's prior experience and his/her effectiveness. In this study, the relevance of a leader's experience, as well as several novel measures of experience, were examined. Two measures of previous leadership experience, experience in the subordinate's job and experience in high stress conditions, were examined as predictors of leader effectiveness. The participants, via archival data, were 29 head coaches in the National Basketball Association (NBA) during the 1996-1997 season. The results indicate that previous leadership experience significantly predicted leader effectiveness after controlling for team member ability and that highly relevant experience was a significantly better predictor than less relevant experience. In addition, experience in the subordinate's job and experience under high stress conditions were significantly related to leader effectiveness and added incremental validity over traditional tenure measures of leadership.