This paper deals with effect of evaporative inlet air cooling on exergy and emission in basic gas turbine cycle. Inlet air cooled gas turbine based power plants are operational in various parts of the world. The article is an attempt to analyze thermodynamic and emission performance to these cycles. Rational efficiency of gas turbine for cooled inlet air at lower relative humidity is higher; also the exergy destruction in combustor is higher among all other components. For a fixed value of equivalence ratio, residence time, turbine-rotor-inlet temperature and two varying relative humidity effect of various values of compressor ratio on primary-zone-temperature, NOx, CO and UHC emission has been analyzed. It has been observed that the primary-zone-temperature and mass of NOX emission increases with increase in compressor pressure ratio whereas mass of CO and UHC emission decreases with increase in compressor pressure ratio. For a fixed value of compressor pressure ratio, equivalence ratio, residence time and turbine-rotor-inlet temperature, primary-zone-temperature NOX, and CO emission increases with increase in relative humidity whereas UHC emission decreases.