The present effort addresses the application of sustainability criteria to the design of "heat sinks" used to cool advanced microelectronic components. The sustainability assessment is based on several criteria, including the use of natural resources, the environment, social welfare, and economic impact. The development of forced convection heat sinks, which are compatible with sustainable development, involves a subtle balance between the achieved thermal performance and the investment of material and energy in the fabrication and operation of the heat sink. It is shown that sustainability criteria can be used to select the environmentally optimal configuration among the most promising heat sink designs, including the lowest pumping power, the least mass of material, and the lowest total (fabrication and operation) energy for a specified application. Of the options considered for cooling a 100 W microprocessor with an aluminum heat sink operating at an excess temperature of 25 K, the heat sink design with the lowest total energy consumption was found to display the highest Sustainability Index.