The complexity of human behavior challenges our explanatory powers. Yet, in this day and age we desperately try to manage and control the behavior of our corporate citizens through rules, codes, systems and procedures alike. This study is an illustration that true human behavior cannot simply be controlled by (more of) such rules. Instead, it is driven by many psychological, cultural, contextual, and environmental factors – amongst which, cultural differences. The focus of this study is the influence of cross-national cultural differences in the context of the professional behavior of auditors, based on the central question: Is auditors’ professional behavior affected by cross-national cultural differences, and, if so, how? Being based on grounded theory, in part validated within an international accounting organization, this study is the first to provide a more profound, in-depth, and contextualized analysis and understanding of the effect of cross-national cultural differences on the behavior of professionals in general, and that of auditors in particular. This study illustrates that international standards are often culture-bound and culture-blind: behavioral drivers, such as one’s cultural programming, determine professional behavior and lead to differences in the interpretation and application of rules and standards. Professional skepticism, knowledge sharing, and partner involvement in the audit team are some of the more significant areas in which the behavior of auditors differs across cultures and are affected by cross-national cultural differences. On a broader level this study is also a call for better recognition of behavioral drivers in the work of professionals and gatekeepers.