In this paper, we examined the psychometric properties of cross-cultural validation and replicability (i.e. measurement invariance) of the Belief in a Zero-Sum Game (BZSG) scale, measuring antagonistic belief about interpersonal relations over scarce resources. The factorial structure of the BZSG scale was investigated in student samples from 36 countries (N = 9907), using separate confirmatory factor analyses (CFAs) for each country. The cross-cultural validation of the scale was based on multigroup confirmatory factor analyses (MGCFA). The results confirmed that the scale had a one-factor structure in all countries, in which configural and metric invariance between countries was confirmed. As a zero-sum belief about social relations perceived as antagonistic, BZSG is an important factor related to, for example, social and international relations, attitudes toward immigrants, or well-being. The paper proposes different uses of the BZSG scale for cross-cultural studies in different fields of psychology: social, political, or economic.