Purpose: This meta-analysis aims to aggregate empirical findings from extant inter-firm opportunism literature. Design/methodology/approach: First, a quantitative summary on the bivariate relationships between the antecedents and the consequences of opportunism is offered. Second, a multivariate analysis is employed to identify significant antecedents of opportunism and the process variables that mediate the relationship between inter-firm opportunism and organizational performance. Findings: Results reveal that goal congruence has the largest influence on inter-firm opportunism, followed by cultural sensitivity, communication, and environmental volatility, norms, governance emphasis, and relative dependence. These important antecedents represent significant research directions for inter-firm opportunism. In addition, inter-firm opportunism affects organizational performance through a mediating process including commitment, functional conflict, overall satisfaction, and trust. Commitment is found to act as a major moderating construct between inter-firm opportunism and its other significant consequences in the revised model. Originality/value: This study widens the horizon on inter-firm opportunism research by examining a much greater number of effect sizes and by employing a more complex framework of the mechanism mediating the inter-firm opportunism-organizational performance relationship and does so more effectively than any individual research work. © Emerald Group Publishing Limited.