Using 437 interviews with apprentices and trainees, teachers/trainers, and supervisors/managers, a study explored retention in apprenticeships and traineeships and factors that influence it. Apprentices and trainees were more likely to complete their contract of training (COT) if they developed an interest in the occupation and had medium- and long-term goals in the occupation, a high level of personal maturity, and support of family/friends/partner; the qualification they were undertaking was perceived to be valuable in the public domain; few alternatives in the occupational area offered better rewards to those without qualifications; they could access resources to cope with changes in personal and workplace circumstances; they developed and used a wide range of skills and knowledge; work hours and demands were realistic and reasonable; work physical conditions were not too onerous; interpersonal relationships were satisfying; management and supervision were supportive; COT length was commensurate with future rewards; there was a high level of integration within the training program; trainers/teachers were seen as experienced in the industry, efficient, and supportive; the COT had some flexibility; all parties recognized and valued the skills and knowledge developed over the COT; and they were supported to develop persistence during training. Possible interventions to enhance retention were suggested. (Appendixes include 36 references, interview schedule, and demographic data on interviewees.) (YLB)