Two studies were conducted to investigate the evolution of 71 Swiss vocational teachers' classroom management as a result of the inputs of a teacher education program, and to identify the factors that encouraged or impeded teacher change. Study 1 consisted of a longitudinal survey, and Study 2 of interviews. Longitudinal analyses were performed using a multilevel approach. This mixed-method study revealed that vocational teachers' classroom management evolved towards the beliefs and practices encouraged by the teacher education program. Years of prior teaching experience and motivations for choosing teaching were found to moderate teachers' evolutions. Moreover, influential people, providing alternative strategies for teachers to try in their classrooms, and questioning teaching practices, were found to influence teachers' change. Finally, this study emphasizes the importance of the congruence between teacher education and the teaching context as well as the influence of school norms on teacher change.