Objective: Mentoring programmes offer an increasingly popular solution to the problem of youth 'at-risk'. While positive outcomes of these programmes are widely documented, there has been little research into the operant processes. The aim of this study was to provide in-depth qualitative information about relationship processes in the Big Brothers Big Sisters of South Africa programme. Method: The sample consisted of mentors and youth in eight relationships. Semi-structured interviews were conducted with the participants and were analysed making use of the narrative method. Results: Relationships were classified into two groups, namely those constructed in terms of their purpose to help the mentees, and those constructed as friendship for their own sakes. These relationships displayed the qualities previously associated with negative and positive relationships, respectively. The results of the study further extend previous findings, revealing the interaction of these overt qualities with underlying constructions of relationships. Conclusion: The study highlights the influence of the programme and broader social context on the mentoring relationships. It indicates the importance of the partners' ability to move beyond the constraints of contextually available narratives of their relationships, and to establish more personal connections, based on the value of the relationship itself, rather than on the programme's ultimate goals.