<p>Thriving at work is noted for its power to produce positive employee outcomes such as psychological health, job satisfaction, and performance. While the majority of current research has focused on the positive outcomes of thriving at work, little attention has been paid to its potential dark side effects, leading to an overly optimistic view of its concept. Drawing upon the theory of PC imbalance and the concept of self-consciousness, we proposed that a thriving employee’s energetic and learning nature is positively related to his or her psychological imbalances (i.e., effort-reward imbalance and challenge-skill imbalance), which in turn induces him or her to perceive overqualification and relative deprivation. We further reasoned that this mediation effect is alleviated by individual future work self salience in the organization. We found support for our hypotheses in a multi-wave study of 412 employees from 6 companies over a period of 14 months. Overall, our studies highlight that although hiring thriving employees may yield many benefits for organizations, such decisions can also lead to potential harm if these employees are wrongly managed. This study makes timely contributions to a more balanced theorization of the effects of thriving at work on both employees and organizations.</p>