Researchers have sought to find the possibility of reflection as a powerful vehicle for successful teaching(Goodell, 2000; Mewborn, 2000; Roth, 2003). As a result, personal reflection in and on action (Schon, 1983) has become a central focus for making changes in practice and developing professional knowledge among teachers (Yerrick, Ross, & Molebash, 2005). Since little is agreed about the nature of reflection in spite of the enormous proliferation of literature on reflection, however, many difficulties and questions have been arisen among teacher educators in integrating reflection into their programs (Ixer, 1999). In the field of physical education, particularly, we need more empirical evidence of impact of reflection on successful teaching (Graber, 2001; Authors, 2005; Macdonald & Tinning, 2003; Tsangaridou, 2005). As a part of a bigger project that explored the nature of exceptional physical education teachers' reflection, the purpose of this study was to describe factors promoting teachers' reflection. This study was grounded in a social constructivist framework and employed a qualitative research method to conduct a multiple case study (Stake, 1995) using in-depth interviews and the non-participant observation method. Participants of this study were three exceptional teachers who earned either the National Board certification or the Teacher of the Year in physical education. The interview and observation data were audiotaped and transcribed. The data were analyzed through the constant comparative method (Charmaz, 2000; Glaser & Strauss, 1967) using computer software for qualitative data analysis (i.e., ATLAS.ti.) as an aid. In order to catch the teachers' real-time reflection, a wireless microphone was used during their teaching, and immediately after teaching, the post-lesson conference (Byra, 1996) on the spot was conducted to help the teachers rethink the teaching moments before they forgot them. Trustworthiness of this study was established by using multiple data sources, member check, and peer debriefing (Patton, 2002). Through the data analysis, five major factors that promoted reflection were identified: (a) students' learning, (b) performance as a teacher, (c) subject matter, (d) professional development work, and (e) educational context. Based on the findings, implications for both pre- and in-service teacher education programs to improve teachers' reflective capacity were discussed in terms of (a) awareness of reflection-in-action, (b) importance of self-reflection, (c) significance of time and opportunity for reflection, (d) development of teaching expertise through reflection, and (e) effect of educational contexts on reflection.Keyword(s): physical education PK-12