Mentoring is presently at the forefront of strategies to improve workplace learning. However, as is often the case, functionalist models of mentoring dominate, and as a result, research on mentoring is rather narrowly conceived. This article was designed to redress this imbalance by critically reflecting on mentoring from contrasting theoretical perspectives. Functionalist conceptions of mentoring construct it as a rational and hierarchical process, often involving an older mentor and a younger learner. In contrast, critical or Radical Humanist conceptions highlight contests for meaning but, more important, want to expose unequal and often exploitative power relations. Many mentoring relationships undoubtedly involve high levels of nurturance, but as this article demonstrates, taken-for-granted practices need to be brought to the surface for mentoring to be regarded as a useful learning tool in todayís work settings.