The breakdown of leadership is a frequent cause for the high failure rate of business process reengineering (BPR). BPR implementation requires a top-down, directive leadership style. Yet, it also requires the management of motivated, skilled people doing non-programmable tasks for which a non-directive leadership style is most suited. This creates an inherent conflict for BPR leaders on choosing the appropriate style to use. Applying the Leadership Effectiveness framework (Flamholtz 1986, 1990), this study conducted in-depth empirical analyses on the relationship between IS leadership behaviors and BPR outcomes for 30 BPR projects. Survey results found that successful BPR leaders use leadership styles that fit the situation better. Also, successful BPR leaders balance their efforts between meeting the needs of the people doing the work and the needs of the work being done. The results of this research provide guidelines for both leadership practices and empirical research.