Performance improvement techniques in power generation systems especially in gas turbine-steam turbine (GT-ST) combined cycle (CC) power plants by compressor inlet air cooling prove to be much improvising. In this work, the performance enhancement of CC power plant by inlet air cooling method using lithium bromide-water (LiBr/H2O) absorption refrigeration system powered by waste heat from heat recovery steam generator (HRSG) have been evaluated and analysed. The results show that CC output always increases but its efficiency increases at certain conditions with incorporating vapour absorption refrigeration (VAR) to CC plant. Coefficient of performance (COP) values of the single effect VAR system is around 0.9 for LiBr/H2O system. A low concentration for weak solution and a high concentration for strong solution have been recommended to get the maximum benefit. The simulated results of plant are validated by considering a case study of existed power plant located at Cochin, Kerala, India and found a close matching.