This paper explores sources of commitment in teachers who have maintained a high level of commitment despite challenging classroom situations. Teacher commitment is important for student success, but can be challenged by negative teacher-student relationships. Eight teachers with a sustained level of commitment for over 15 years were selected for interviews. The semi-structured interviews were transcribed and accounts where the teachers reported on some kind of problem with student behaviour were analysed. Three main sources of commitment in challenging teacher-student relationships were indicated: reconceptualization of problems into intellectual challenges, a sense of professional responsibility for students in problems and confidence after student success against the odds. Learning from those teachers who have managed to maintain their commitment to students despite relational challenges provides important clues to sources of and conditions for commitment.