Abstract: In this paper the performance of a vapour compression refrigeration system with ZrO2 nanoparticles in the working fluid was studied. Nano refrigerant was synthesized on the basis of the concept of the nanofluids, which was prepared by mixing ZrO2 nanoparticles with R152a refrigerant. The conventional refrigerant R134a has a global warming potential (GWP) of 1300 whereas R152a has a significant reduced value of GWP of 140 only. ZrO2nanoparticles with R152a refrigerant were used in R134a refrigeration system. The system performance with nanoparticles was then investigated. The results indicated that ZrO2 nano refrigerant works normally and safely in the system. The ZrO2 nanoparticle concentration is an important factor considered for heat transfer enhancement in the refrigeration system. The concentration of nano ZrO2 ranges between 0.01% and 0.06% volume concentration with particle size of 20 nm with R134a and R152a was studied. The coefficient of performance of the system was significantly improved with 33.45% when 0.06%volume concentration of ZrO2 with R152a refrigerant was used. The discharge temperature of the R152a/ZrO2 Nano refrigerant was nearly same as that of R134a. The usage of R152a with zero ozone depleting potential and very low Global Warming Potential provides a green and clean environment.