Although mentoring provides numerous benefits to individuals in organizations, there can be negative aspects in formal mentoring relationships. Drawing on previous research on mentoring and personality traits, we theoretically examine the antecedents and consequences of prot?g?s’ negative experiences in formal mentoring, such as distancing and manipulative behaviors exhibited by their formal mentors. This paper identifies two personality traits - machiavellianism and equity sensitivity ? as the dispositional antecedents of negative mentoring and explains how each may be related to distancing and manipulative behaviors exhibited by formal mentors toward their prot?g?s. We suggest that the characteristics of the formal mentoring program can moderate the relationship between such personality traits and negative behaviors. Then, we propose some propositions reflecting the effects of negative behaviors on prot?g?s’ attitudes. This conceptual paper extends mentoring research by comprehensively considering the negative side of mentoring.