Mentoring is a popular workplace practice, bolstered by a substantial body of literature that has underscored its positive outcomes for protégés and organizations. Less pronounced are the potential risks and costs associated with workplace mentorship. In this article, we consolidate what is known about workplace mentorship and draw on organizational justice research, self-determination theory, and findings related to indirect exposure to expand on the potentially darker side of workplace mentorship. Our comprehensive review suggests that workplace mentorship appears to have positive consequences in particular circumstances for particular groups of employees, but the conclusiveness of its positive effects is limited by significant gaps in the research. To assist in determining if the potential benefits outweigh the potential risks and costs, we offer a list of considerations for individual employees who are considering engaging in a mentoring relationship and for those implementing workplace mentoring programs.