The techno-economic performance evaluation of a combined cooling heating and power (CCHP) system installed in a hospital building in Greece is presented. The aim was to verify performance standards and evaluate real behavior, while highlighting the economic gains. In this research, system performance was evaluated using actual and year-round field measurements. The data were used to calculate the recovered heat and the generated electric energy. Furthermore, the performance was modeled and compared to the manufacturer specifications. Financial assessment was conducted through energy cost analysis to verify the operating viability of the system, both for its heating and cooling functions. The results showed that, overall, after eight years of operation, the energy efficiency was still within design standards. Electrical efficiency was constantly above 30%, while thermal efficiency was around 40–45%. Total efficiency was usually above the 75% threshold, characterizing the system as fully CHP operating. The analysis also pointed out the economic effectiveness of the system in the Greek energy market. The results verified the potential of a CCHP system for improving the energy and economic performance of a building.