The PhD by project entitled ‘Leadership practice in leadership programs: An action research project’ has investigated changes in the practice of twenty-five managers who undertook a year long Graduate Certificate in Organisation Leadership (GCOL) at RMIT University in 2002, 2003 and 2004. This project was designed to provide insight into the educational effectiveness of the program through an analysis of data from the three action research cycles. A co-operative inquiry approach was utilised to gather their reflections on the program and insights into changes in participants’ organisational leadership practice. <br><br>As well as data collected during the program, in action research cycles, post program interviews (PPI) were undertaken with twenty of the twenty-five participants (five could not be successfully contacted) some eighteen months after their completion of the GCOL in order to ascertain its impact on their leadership and management practice. Because the interviewees became well known to the researcher, considerable depth of understanding was achieved by the research and the data to meet the ‘strong criteria’ of validity as outlined by Miles and Huberman (1994, p. 268). The data provided the basis for the development of a Model of Leadership and Management Practice Development (MLMPD) a product of the PhD research. <br><br>Further contributions of this research included, insights to better practice in teaching leadership and management programs, further understanding of processes of co-operative inquiry as a method of facilitation of learning in an adult learner context, and a portfolio of learning materials to provide insights for fellow facilitators the processes, content and context of learning in this co-operative inquiry based learning project. <br><br>