Trust and mentoring are two well researched concepts within the field of management science. However, very few studies have sought to explicitly look at the role of trust in the mentoring relationship. This study seeks to contribute to the linking of the two fields. The mentoring experiences of 289 second year trainee lawyers who were interns in law practices in the Republic of Ireland were surveyed. Their levels of trust in their formally assigned mentor was assessed and their perceptions of the effectiveness of their mentoring experience using Scandura's (1992) three function conceptualisation were measured. The role of trust in the experience of the three functions is highlighted. The research also reveals how trust in mentor and the experienced career development aspect of mentoring, predict trainee intention to stay or leave their organisation. Implications for mentoring programme development and practice are suggested.