In general, it is ben eficial and adaptive to have high self-esteem; however, contingent self-esteem depending on approval is not so advantageous. This article presents research on a Polish version of the Contingent Self-Esteem Scale (CSES), which measures contingent self-esteem. The CSES was administered on a total of 1,199 participants; a range of other instruments were also used to establish the validity of the CSES. The CSES proved to have acceptable internal consistency and validity and factor analyses revealed that it contains four factors: vulnerability to negative opinions, dependence on physical attractiveness, dependence on opinions, and dependence on self-standards. Contingent self-esteem was positively correlated with neuroticism, agreeableness, ruminating, anxiety, and maladaptive perfectionism; it was negatively correlated with general self-esteem and self-efficacy. Mediational analyses confirmed the hypothesis that low general self-esteem causes high rumination about oneself, which in turn is related to high contingent self-esteem.