Based on a study on vocational training dropout, this contribution focuses on the relationship between trainers and apprentices, from the apprentices’ viewpoint. First, interviews with apprentices stressing bad relationships are analysed. This points out how these young people define a « bad relationship » as well as its effects on the training. Positive relational situations are then analysed in order to illustrate what apprentices put forward and to point out the way in which a good relationship can promote knowledge transmission. Finally, these elements reveal apprentices’ expectancies toward the trainers. Results confirm that relational aspects are important both for the transmission of knowledge and for the quality of the school-to-work transition.