This paper experimentally investigated the thermal performance of a miniature vapor compressor refrigeration system using a thermal resistance model for electronic cooling. The evaporator, compressor, expansion valve, and condenser are the four main devices forming the refrigeration system with R-134a as a working fluid. The experimental parameters considered were the openings of the expansion valve and input heating power. The results indicated that the system in this paper had the largest cooling capacity of 150 W and coefficient of performance of 4.25 at the 8th and 9th openings of the expansion valve, respectively. The results also showed that correlations of the thermal resistance of the evaporator and the condenser are developed with experimental data and their precision, compared with the experimental data, was about 4.42% and 12%, respectively. Besides the adjustment of the compressor speed could decrease the possibility of the occurrence of condensation phenomena near the inlet and outlet of the evaporator. Also, the smallest dimension of the combination of the evaporator and condenser is presented at the input heating power of 150 W and the 8th opening of the expansion valve.