Abstract The thermodynamic analysis of the Stirling cycle presented here accounts for the effects of two important design parameters, namely dead space and imperfect regeneration. The definition of the refrigerating efficiency introduced here ensures a fruitful comparison of cycle performance with dead volume and without dead volume. Modified time displacement and pressure volume diagrams are also presented for the Stirling cycle with dead volume. The calculated theoretical results are also presented to illustrate the influence of the temperature ratio, volume compression ratio, regenerator effectiveness, dead volume ratio and the effect of working fluids on the coefficient of performance and refrigerating efficiency. Optimization charts for maximum refrigerating efficiency are also included.