Considering corruption as one of the chronic harms of the administrative system, and the social factor affecting economic growth, the present study sought to explain, for the first time, the differences in the perceived levels of corruption among 16 Southwest Asian countries, relying on the sociological “, new institutionalism”,theory in analyzing organizations, describing causal mechanisms and their mutual impact, and creating corruptive contexts. The fuzzy-set Qualitative Comparative Method ((FSQCA)) and the secondary data were used to find the causal configurations leading to corruption in these cases. The experimental judgment led to two causal configurations showing that some institutional requirements of the institutional environment, in contrast to the requirements of the technical environment, exacerbated the gap between formal and informal structures. Conflicts lead to the formation of informal norms and networks that, over time, provide shared mental patterns for actors in executing current actions and confronting ambiguity and uncertainty,and on the basis of contextual rationality, they are interpreted as an appropriate way of acting. This reduces the costs of corruption and increases the opportunity for abuse by diminishing supervision and control and strengthening informal networks.