Thermodynamic analysis of an ideal air-standard Miller cycle is presented in this paper. The paper outlines the effect of maximizing power density on the performance of the cycle efficiency. The power density defined as the ratio of the power to the maximum cycle specific volume. Although the efficiency of Atkinson and Joule-Brayton cycles at maximum power density is greater than that of Miller cycle, it is important to note that the total cycle volume and pressure ratio at maximum power density of Miller is smaller. The results obtained from this work can be helpful in the thermodynamic modeling and in evaluation of Miller engines over Atkinson and Joule-Brayton engines.