A Monolithic Integrated Circuit (MMIC) cooling structure having a heat spreader thermally comprising a anisotropic material, such material having anisotropic heat conducting properties for conducing heat therethrough along a preferred plane, a surface of the MMIC being thermally coupled to the heat spreader, the preferred plane intersecting the surface of the MMIC; and, a thermally conductive base having a side portion thermally coupled to the heat spreader, the side portion being disposed in a plane intersecting the preferred plane.