The study aims to shed light on whether mentoring may help proteges decrease their perception of job content plateaus. Based on the conservation of resources theory, career mentoring could be an effective resource in decreasing job content plateaus and alleviating the resulting emotional exhaustion. The study also proposes that perceived organizational support (POS) can be an organizational resource for proteges, strengthening the effects of career mentoring in addressing the problem of job content plateaus and ensuing emotional exhaustion (via job content plateaus). Two-wave data were collected from a sample of 353 proteges in Germany. Results showed that career mentoring was negatively related to emotional exhaustion through job content plateaus. Moreover, high POS strengthened the effects of career mentoring, directly in dealing with the issue of job content plateaus and indirectly for emotional exhaustion. Important theoretical and practical implications for mentoring and career plateau research are discussed.