The authors analyse epistemological beliefs and their relationship to the knowledge developed by students engaged in a reorganized programme of training for secondary school teachers in Quebec. They examine two contexts for initial training: the training in their discipline that university students follow, and the practical training students undertake in the school environment. Qualitative data were obtained through critical exploration (Piagetian) interviews with twelve pre-service teachers. These results made it possible to outline multiple epistemological postures, and to describe the tensions between the subject-related and practical aspects of initial training. In particular, based on an analysis of their epistemological beliefs and their relationship to knowledge, it would appear that pre-service teachers develop a less refined approach through practical training than they attain at university. Finally, the authors raise some issues concerning teacher training.