We document in this study that high religious environment in which auditors operate have a significant impact on their behavior, resulting in lower audit risk and lower audit effort, and hence lower audit fees. Our findings show that there is a significantly negative association between audit fees and religiosity values of counties in which auditors’ offices are located. Additionally, the results show that only the religiosity values based on Protestants’ religious beliefs are negatively associated with audit fees, but not the religiosity values based on Catholics religious beliefs. Moreover, we find that the negative association between religiosity values and audit fees is stronger when auditors’ offices are located in rural areas compared to urban areas. We use the religiosity values based both on the American Religion Data Archive (ARDA) and Gallup data base to enhance the reliability of our results, and we find that the results based on both data bases are similar.