Multisource ratings and feedback are now central components of many leader development programs. Research evaluating the outcomes of multisource feedback (MSF) underscores the importance of facilitation strategies that help leaders to interpret and use their feedback throughout the development process. Scholars and practitioners have recommended executive coaching as one such facilitation strategy. However, there is little empirical basis to substantiate the benefits of executive coaching beyond other less costly strategies, most notably feedback workshops with groups of leaders. This quasi-experiment followed 469 managers from a large government agency participating in a 15-month leader development program. Changes over time in MSF ratings of leadership behaviors and effectiveness were compared for two groups of leaders. The first group of uncoached managers participated in a feedback workshop shortly after the premeasure MSF, and the second group participated in the feedback workshop plus several sessions with an executive coach thereafter. Results indicated that managers in both groups improved similarly as rated by direct reports, peers, and supervisors, whereas only those managers who received the executive coaching improved according to self-ratings. Specifically, the executive coaching intervention had a unique positive effect on managers' self-rated involvement, consistency, and mission-focused leadership behaviors. These findings are discussed in light of "psychometric" and self-efficacy perspectives, and in relation to exploratory regression analyses linking managers' self-ratings to others' ratings of their effectiveness at the conclusion of the program. (Contains 6 tables and 2 figures.)