Choral singing is a key feature of musical activity in Hong Kong schools. It has grown from modest beginnings into an important part of extra-curricular work. Even in independent societies and associations, many choral directors possess backgrounds in music education and classroom teaching. The teacher education institutions are responsible for training the majority of music teachers in Hong Kong. Thus it would seem necessary for music teacher courses to feature choral training to properly equip teachers before entering the classroom and taking the role of choral director in class, school and perhaps community. In the past there has been no choral director training programme. It seems important to develop ideas for what might be included for the professional development of the student choral teacher, and this is one objective of the current study. This article reports the implementation of a mentoring scheme carried out in a primary school setting. One of the current authors and an identified school choral teacher worked as mentors to provide professional support for a student choral teacher who was selected as the main participant in the case study. The aim was to investigate the potential of mentoring as a way of training a student choral director in a real school setting. Findings from this study reveal that through the mentoring scheme the student choral teacher was provided with an opportunity to interpret, generate, interact and experiment with the choral teaching theory in a real school choral rehearsal setting. This could be seen as a process of knowing-in-action and reflection-in-action.[Copyright © 2006 The Hong Kong Institute of Education, International Society for Music Education.]