Based on neo-institutional literature, this article aims to show the influence of organizational isomorphism on corruption. The focus is institutional explanations of corruption. Our model is based on empirical research in Russia at the end of the 1990s. A face-to-face questionnaire was conducted with 552 top executives in private firms across various economic sectors. We used the structural equation model Partial Least Squares, PLS, technique to test our hypotheses. The developed model provides an integrated approach to the study of the relationship between corruption and organizational isomorphism. Our empirical data from firms in Russia allowed us to test various theoretical hypotheses concerning the influence of organizational isomorphism on corruption. Our emphasis is on the influence of competitive and institutional isomorphism on corruption.