The purpose of this research is to investigate the relationship between the knowledge of the audit committee and the delay in issuing the audit report and the audit fee in the audit institutions of Tehran. The method of this research is applied and of the descriptive-correlation type. The statistical sample of this research was made up of 136 senior employees and managers of auditing companies in Tehran. The tool for collecting information in this research is a standard questionnaire, the first part of which is related to demographic questions, and the second part includes 3 questionnaires on the knowledge of the audit committee, delay in issuing the audit report, and the audit fee, which were evaluated on a Likert scale. In order to analyze the collected data, descriptive statistics methods such as (frequency, graphs, mean and standard deviation) and inferential statistics (Pearson correlation) were used. It should be mentioned that all statistical steps were analyzed by SPSS24 software. The results of the research findings showed a positive and significant correlation between the knowledge of the audit committee and the delay in issuing the audit report and the audit fee in the audit institutions of Tehran. As the knowledge variable of the audit committee had an effect on the delay in issuing the audit report and the audit fee in the audit institutions of Tehran. Therefore, it is suggested that the managers of the audit institutes, according to the knowledge of the people, form an expert audit committee in their institute in order to be effective in the process of audit report and audit fee.