The performance of a thermoelectric refrigeration device, consisting of multi-couple thermoelectric elements and operating between two heat-reservoirs at constant temperatures, is investigated. The influence of the external and internal irreversibilities of the thermoelectric refrigeration device on the performance of the system is analyzed. The general expressions of the coefficient of performance and power input are derived by introducing some dimensionless parameters and variables. The coefficient of performance of the refrigeration device is maximized for a given cooling-load and total heat-transfer area of the system, and consequently, the structure parameters of the device and the area ratio of the heat exchangers of the system are determined optimally. The effects of the various parameters on the optimal performance of the device are discussed further. The results obtained here will be useful for a more detailed investigation and for the optimal design and manufacture of real thermoelectric refrigeration devices. (c) 2007 Elsevier Ltd. All rights reserved.