Glass door merchandisers are used to display chilled beverages or refrigerated foods in grocery and convenience stores. Carbon dioxide (R744, CO2) is seen as a promising low global warming potential refrigerant alternative for this application that is non-flammable and non-toxic. In this present study, the performance of the R744 glass door merchandiser refrigeration system has been further improved by implementing a two-phase ejector cycle. Previous ejector studies have mainly focused on larger residential or automotive air-conditioning, heat pumping, and supermarket refrigeration applications; the implementation of an ejector in smaller systems presents challenges in terms of low-cost ejector design and simplified cycle control. Different ejector cycles are discussed to compare the advantages of each cycle when used in a smallscale system. A low-cost design has been devised and implemented. Performance of the improved system is compared against the baseline without ejector.