The purpose of this study is to evaluate the efficacy of a feedback and coaching intervention designed to improve the quality of principal leadership. Principals received feedback from teachers on their instructional leadership, and their teachers' trust of them. Principals also provided self-ratings and they compared their teachers' ratings to their own self-ratings. In the first part of the study they received feedback reports of these data. In the second part they worked with trained coaches on how to use and integrate that information into their educational practice. The authors predicted that this intervention would improve principals' leadership, trust, and, ultimately, enhance student achievement. (Student achievement was not evaluated in this project). The first hypothesis about feedback was tested in a longitudinal randomized design and the second concerning the addition of coaching in a pre-post design where principals received feedback only in the first year and feedback and coaching in the second year. The results indicate that teachers' perceptions of instructional leadership and trust of their principal can be enhanced when principals are provided with feedback alone. However, when coaching is added the effects are much more powerful and depend on the principal's perception of the validity of the feedback and the number of coaching sessions attended. This study provides new experimental evidence of the efficacy of feedback and coaching as a program for leadership change and development aimed at improving instructional leadership and teacher-principal trust. Appended are: (1) References; and (2) Tables and Figures. (Contains 3 tables.)