Organizations have been modifying performance appraisal systems to collect data from multiple sources to guide supervisor development. Multiple rater programs provide leaders with more than one source of feedback, and give them a more complete, and possibly more accurate picture of their performance, which can facilitate meaningful behavioral change. The purpose of this thesis was to develop and validate a Leadership Commitments Inventory (LCI) from a 360-degree feedback approach that reflected a six-factor leadership taxonomy composed of twelve distinct indices. Using successive content adequacy tests, 48 items were validated and the web-based LCI was administered to 278 participants. Internal consistency estimates for the twelve commitment scales differed for supervisors and observers. The internal consistency estimates (indexed by Chronbach's alpha) for supervisors ranged from .27 to .79 (8 of 12 were .68 or greater). Internal consistency estimates for the observer sample were much better, with all twelve scales greater than .70. A nested confirmatory factor analysis using LISREL demonstrated that the hypothesized six-factor model clearly provided the best explanation of the LCI's underlying factor structure, with 11 of the 12 commitments loading on their hypothesized practice. The instrument is now available on the Internet for supervisor's who wish to develop into better leaders.