The purpose of this study was to investigate the reliability and validity of the Korean version of zero-sum belief scale in a sample of Korean adults 19 years and older. The scale was originally developed by Różycka-Tran, Boski, and Wojciszke (2015) based on the Belief in a Zero-Sum Game (BZSG) model A total of 508 participants (252 college students and 256 non-student adults) completed an online survey comprised of zero-sum belief, social trust, subjective socioeconomic status, individual-collectivism, and comparison orientation scales. The results of an exploratory factor analysis and a confirmatory factor analysis indicated that zero-sum belief scale has one factor. The internal consistency of the zero-sum belief scale was good. Zero-sum belief scale did not have a significant relationship with social trust and socioeconomic status. However, the scale was positively associated with vertical individualism and vertical collectivism, and negatively related to horizontal collectivism. There was no significant relationship between zero-sum belief and horizontal individualism, but there was significant positive relationship between zero-sum belief and comparison orientation. This study could facilitate future research on zero-sum belief in South Korea, and future studies need to explore the predictors and effects of zero-sum belief.