This article is aimed at carrying out a performance analysis of a combined cycle gas turbine power plant with various inlet air-cooling systems. A comparison is performed using different cooling systems, including evaporative cooling, fogging, mechanical (electric) chiller cooling, and absorption cooling. A performance analysis is completed for each system. The performance characteristics are determined for a set of actual operational parameters including ambient conditions (temperature and relative humidity), turbine inlet temperature, pressure ratio, etc. To evaluate the net power output and efficiency for each system, a combined cycle unit system consisting of inlet air cooling system, gas turbine, dual pressure heat recovery steam generators, and steam turbine has been analyzed. The results show that power and efficiency improvements depend on ambient air temperature. In addition, by decreasing the ambient temperature and increasing the humidity of the air, the output power can be increased. The carbon dioxide emissions for each cooling system are also discussed. The results and the sensitivity analysis show that the absorption cooling system is most effective.