The effectiveness of the Instructional Partnership Network (IPN), a collaborative initiative that provides professional development to school principals, has not been previously measured. An investigation of the impact of this state initiative on teacher efficacy, teacher trust in colleagues and teacher trust in the principal was conducted. The rationale for this study is that behaviors promoted by the IPN such as principal instructional leadership, promoting collaboration, and empowering teachers are believed to have a positive impact on trust and efficacy. This study developed a measure to determine the level of implementation for the IPN. The Principal Behavior Scale (PBS) was developed based on IPN principles. Other instrumentation utilized for this study included the Teacher Sense Efficacy Scale, Faculty Trust in the Principal Scale, and Faculty Trust in Colleagues Scale. 242 teachers from sixteen elementary schools within the Tuscaloosa City and County school systems completed surveys for this study. The results suggested that participation in the IPN resulted in teachers having higher levels of trust in their principals. However, the teachers who worked in schools that were part of the IPN program did not have significantly higher levels of teacher efficacy or significantly higher levels of trust in their colleagues than the teachers who worked in schools that were not part of the IPN program. The result also showed that perceptions about the implementation of the IPN program did account for differences in teacher efficacy, teacher trust in principals, and teacher trust in colleagues among IPN schools.