Two studies were conducted to operationalize the construct of negative mentoring experiences, establish content validity, and test theorybased predictions associated with a nomological network of related variables. As predicted, the negative experiences of mentor Distancing Behavior and Lack of Mentor Expertise were more often reported in the separation phase and among prottgts in formally arranged mentoring relationships. All types of experiences were related to careerrelated support, psychosocial support, and learning, with Distancing Behavior being most highly related to career support and learning. Significant correlations were also found with relational complementarity, social exchange perceptions, intentions to leave the relationship, depressed mood, and psychological job withdrawal. Negative mentoring was also distinct from positive mentoring, general workplace stress, and dissatisfymg social relationships at work, providing discriminant validity evidence. Finally, negative mentoring had explanatory power in predicting protCgCoutcomes over and above positive mentoring. The findings are discussed in terms of future research on mentoring as well as applied practice.Mentoring refers to an intense interpersonal relationship between a senior, more experienced individual (the mentor) and a junior, less experienced individual (the prottgt) whereby the mentor provides career and personal guidance to the protCgC (Kram, 1985). Mentors provide two types of support to prottgts. Career-related support involves the mentor actively working to increase the prottgt's visibility within the organization and providing high quality developmental experiences. Psychosocial support refers to the extent of intimacy, friendship, and trust between mentor and prottgt. Mentoring is associated with salary growth,