The Global Belief in a Just World Scale (GBJWS) has been widely used in measuring the Belief in a Just World (BJW) personality trait. Despite its widespread application across the social sciences, the validity of this scale has not been sufficiently tested in the literature. In this research, the authors examine the internal and external validity of the GBJWS using both standard correlational analyses and structural equation modeling (SEM). Specifically, the authors test the concurrent validity, internal consistency, uni-dimensional structure, convergent validity, and both measurement and latent mean invariance of the scale across gender and culture. The results of a pilot study suggest strong concurrent validity of the GBJWS with other BJW scales, and the findings of the two main studies support the internal and external validity of GBJWS across gender and culture. The authors' results further show an overall greater level of BJW of Chinese individuals compared to Americans. The present research provides a much needed investigation of the validity of the GBJWS, and answers calls for research examining the scale's utility across different populations. (C) 2015 Elsevier Ltd. All rights reserved.