To optimize decisions related to drilling and well planning in high pressure areas, pore pressure estimation is of high necessity. Nowadays, certain methods are not available for pore pressure estimation and researchers are making some efforts to provide some. The research has been performed to the aim of pore pressure estimation through different methods, as well as comparing their efficiencies and accuracies for one of the oil fields located in south-western part of Iran. The pore pressure is estimated using Eaton, Bowers, Dutta, Tau and Modified Eaton's method at location of well. The study results show that pore pressure estimated through modified Eaton’s method has higher correlation with data related to pore pressure measured at location of the well under study. According to the comparison performed, modified Eaton’s method would be used to obtain cube of pore pressure within the limits of the field under study and The pore pressure distribution and effective stress distribution map are plotted in the reservoir area.