Whereas core self-evaluation (CSE) has been proposed as an antecedent of creativity, surprisingly, little research has examined it. Extending prior research on CSE, this study investigates when and how CSE relates to creativity. Drawing on the approach/avoidance theoretical framework (Elliot & Thrash, 2002), we propose that employee’s knowledge sharing behavior serves as a mechanism that links CSE to creativity. We further examine the positive moderating effect of work meaningfulness as an activator of the approach tendencies of high-CSE employees. We tested our hypotheses using two-wave multi-source data from a sample of 200 researchers and their supervisors. The results fully supported our hypotheses, and offered both theoretical implications and practical implications.