Thermal management of electronics is vital to the successful design, manufacture, and tactical operation of a variety of military electronic systems. Designs employ all modes of heat transfer including: conduction, natural and forced convection, aerodynamic heating, radiation, and two-phase heat transfer. A variety of heat sinks and heat exchange devices are employed, including the use of cold plates, electronic chassis coldwalls, compact heat exchangers, air-cycle and vapor-cycle refrigeration systems, phase change materials, thermoelectric devices, and heat pipes. This paper describes several military electronic systems on a variety of platforms and discusses the thermal management issues involved in the design of the thermal control systems. Specific examples are employed in the paper to emphasize the variety of thermal management problems encountered and the solution techniques employed.