This study is concerned with school-based staff development. It looks briefly at the reasons for this development, emanating from changes in society and schools. First it traces the growth of school-based staff development overseas and in Australia. A variety of approaches to school-based staff development activities is demonstrated by a selection of case studies in the United Kingdom, United States and Australia. The study then examines staff development provisions in the ACT education system, a system based on the philosophy of participatory decision making. It then looks closely, by means of description and questionnaire, at staff development in a particular school in this system, Duffy Primary School. The study concludes with recommendations and a model for staff development in schools. The writer implemented a school-based model of staff development at Duffy Primary School independent of other current theories and practices on school-based staff development. His most recent reading and research outlined in this study have confirmed the basic soundness of the school-based model of staff development.