Thermoeconomic optimization of simple refrigerators is formulated and applied to a specific case. Condenser and evaporator areas and compressor efficiency are selected as the independent design variables of the system components. Exergy analysis is carried out to find local and total irreversibilities. Costs assigned for exergy losses are combined with capital and recovery costs, and equations for thermoeconomic optimum of components are derived. Finally, as a case study, the equations are solved to determine the thermoeconomic optimum refrigeration system of a domestic refrigerator whose cooling load and operation temperatures (inner and outer) are specified.