In this paper, the effects of various compressor inlet air cooling methods to increase the performance of Shahid Hashemi-Nezhad gas turbines refinery were investigated. These methods included media, fogging, and absorption chillers as common inlet air cooling methods and pressure drop station as novel cooling method. By using the exergy, environmental, and economic analysis, the best method for compressor inlet air cooling was selected. Based on the results, the absorption chiller system had the highest compressor inlet air temperature drop and increased the thermal and exergy efficiencies of cycle by about 2.5 and 3%, respectively, in hot season. Using absorption chiller, pressure drop station, fogging, and media had further reduction in CO2 and CO than simple gas turbine, respectively. Finally based on the net present value and internal rate of return coefficients, the pressure drop station method is the most economically feasible option.