This study examines the theory-and-practice connection model in mentor preparation in the context of two mentor preparation programmes in Hong Kong. The 30- and the 60-hour mentoring support development (MSD) programmes share a common conceptualization of mentoring--with the improvement of teaching and learning as the core of mentoring--yet they differ in objectives, duration and the mentoring practice settings in which structured practical work occurs. This enquiry addresses how the theory-and-practice connection model contributes to the construction of professional knowledge in mentoring and the development of mentoring practices in schools. It was found that the organization of curriculum components, such as coursework (e.g., skills of lesson analysis and conferencing), and structured practical work in mentoring, facilitated the connection of the theory and practice of mentoring. In addition, mentor trainees (practising school teachers) developed competence in mentoring through integrating research-based knowledge and knowledge that grew out of their own mentoring experience. Finally, suggestions for the design of mentor preparation programmes and workplace conditions that facilitate mentoring in schools are discussed. (Contains 4 tables and 2 notes.)