Staff development of teachers has been a major topic in the literature over the past decade. The literature has pointed out the shortcomings of traditional staff development while suggesting that school-based staff development can better meet teachers’ needs in the future. Three suburban public intermediate schools entered into a collaborative approach to staff development in order to bring about a more school-based staff development program. The collaborative approach included a team of teachers and a principal from each school participating in a graduate level course together. One outcome of the course was long-range staff development plans developed by each team based on the needs of each individual school. The purpose of this study was to examine the efficacy of the collaborative school-based staff development approach in terms of the process, comparison to other intermediate schools, and the product (staff development plans). Seven research questions were answered in this study from the data generated by structured interviews of principals and teachers from the three collaborative schools and three similar noncollaborative intermediate schools as well as the staff development plans from the three collaborative schools. Findings from the study indicated that the process of the collaborative approach to school-based staff development was generally perceived as having much potential and favored over the traditional approach to staff development. Nevertheless, there was considerable dissatisfaction about the design and delivery of the course. Many recommendations for improvement of the collaborative approach were made by course organizers, principals, and teachers. There were both similarities and differences in the staff development programs in the collaborative schools as compared to noncollaborative intermediate schools as reported by both principals and teachers. Teachers reported similarities in staff development activities, communication, and strengths. Differences in perceptions included needs assessment, decision-making, and improvements needed. Principals reported the same similarities as teachers except strengths which were viewed differently. The nature of the staff development plans and their initial implementation varied from school to school. Case A focused on communication within the school and student organization. The plan was perceived as making a positive difference in both areas. Case B focused on orientation of new teachers to the building. Due to a boundary change, no new teachers were added to the staff and the staff development plan was not implemented. Case C focused on improving school climate with three specific emphases over three years: instructional technology, characteristics of the middle school student, and higher level thinking skills in under-achievers. The plan was perceived as making a positive difference in the school. / Ed. D.