In recent financial scandals, related parties transactions (RPTs) have been as one of the major concerns, so that the targeted use of these transactions and lack of their disclosure or insufficient disclosure are some of the factors in the failure of the corporates. In RPTs, there is a risk that the related party may be favoured with terms that could harm the interests of the company’s shareholders. The purpose of this study was to investigate the effects of different types of related parties transactions on the firm value with the moderating role of the audit committee incorporates listed in Tehran Stock Exchange. The research statistical sample consists of 100 listed firms in the Tehran Stock Exchange in 6 years of 2013-2018. This research, based on the nature and content, is a descriptive/ correlational research. Using Panel data and multiple regression, the results of the research show that there is a negative relationship between RPTs and the firm value. The findings also show that there is a positive relationship between the audit committee and the firm value. Also, the findings show that different types of RPTs have a different effect on the firm value. The results also show that the audit committee does not affect the relationship between RPTs and the firm value.
