This paper reviews the literature on informal mentoring at work. Based on two basic premises of interpersonal relationships, it discusses four promising areas in current mentoring research that could be cultivated further by future research. The first premise that we hold is that relationships never exist in a vacuum. Traditionally, however, mentoring literature has often overlooked the context of mentoring. We propose that the developmental network approach can be further extended to gather more insight into the interplay between mentoring dyads and their context. Also, mentoring literature could pay more attention to temporal influences in mentoring studies. The second premise that is applied is that relationships are not only instrumental in nature. However, mentoring research to date has mostly applied a one‐sided and transactional view to mentoring. Relational mentoring theory could be helpful in examining relational motivations of both members. Also, mentoring literature can achieve more explanatory power by examining the underlying mechanisms of mentoring, next to social exchange principles, that cause these developmental changes. In summary, in each of these four research areas, we identify and discuss fundamental questions and developments in research that can advance mentoring theory and practice.