The purpose of the present study is the impact of financial auditing by large auditing firms on the quality of corporate social responsibility. This study included companies that were members of the Tehran Stock Exchange Organization from 2011 to 2012. Based on systematic exclusion, 213 companies and 2556 company-years were selected as a statistical sample. In the present study, the method of collecting information was library-based and the data related to the statistical sample was collected through the Kodal website. To explain the explanatory power of the explanatory variables, the adjusted coefficient of determination was used, to examine the significance of the variables, the t-statistic, and to examine the overall adequacy of the model, Fisher's F-statistic was used. Statistical analyses were also performed using EXCEL and EVIEWS software. Library methods were used to collect information related to the literature on the subject and the background of the research. If we consider the classification of research according to purpose, the present study is in the category of applied research, if we consider the classification of research types based on nature and method, the present study method is in the category of descriptive research in terms of nature. The results of the research hypothesis test showed that financial auditing of large auditing firms has a significant effect on the quality of corporate social responsibility.