Abstarct: From petroleum geochemistry perspective, the source rock plays a crucial role as the most significant element in petroleum systems. A source rock is a rock that is capable of generating oil and gas, or oil and gas have been produced from it. Considering the importance of the source rock, its identification and evaluation are very essential and necessary for petroleum exploration. One of the key parameters that significantly affects the identification and evaluation of source rock is Total Organic Carbon (TOC) content. This parameter is an indicator of the richness of organic matter present in the source rock, as well as the ability of the source rock to generate hydrocarbon. The main objective of this study is to estimate the TOC content using petrophysical methods and compare them with TOC values measured by the Rock-Eval pyrolysis analysis, in order to determine the best petrophysical method for estimating the TOC. In this study, four cutting samples from the Gadvan Formation in well A, one of the hydrocarbon fields in southwestern Iran, were examined and geochemically evaluated by Rock-Eval pyrolysis. The analyses showed that the Gadvan Formation in the studied field has a relatively good to good level of organic matter richness, and its kerogen is type II. In terms of thermal maturity of the organic maters present in the rock, out of the four studied samples, two samples are thermally mature and are in the oil generation window, while the other two samples are at low thermal maturity. In this research, to estimate the TOC content by petrophysical methods, the wire-line logs of well A in the studied field, and petrophysical methods of ∆logR, Schmoker and Hester, and Bulk density (Renchun) were investigated. Next, the TOC values obtained from the Rock-Eval analysis were compared with the values estimated by the mentioned methods. The comparisons indicated that the ∆logR method with RMSE error rate of 1.36 has the highest error, while the Schmoker and Hester and Renchun methods have the lowest error with RMSE error rate of 0.5 and 0.4, respectively. Therefore, for estimating the TOC value in other wells of the studied field that do not have rock samples, the Renchun method is the best petrophysical method. Consequently, these method were utilized to estimate the TOC content of the Gadvan Formation in wells B and C of the studied field.