Copper-matrix SiC whisker composites containing 33-54 vol % SiC whiskers and with < 5 vol % porosity were fabricated by hot pressing SiC whiskers that had been coated with copper by electroless plating followed by electroplating. The highest Brinell hardness of 260 was attained at 50 vol % SiC whiskers. The lowest coefficient of thermal expansion (CTE) of 9.6 x 10(-6)degrees C-1 (at 25-150 degrees C) was attained at 54 vol% SiC whiskers. The composites exhibited lower porosity, higher hardness, higher compressive yield strength, lower CTE, lower electrical resistivity and higher thermal conductivity than the corresponding composites made by hot pressing mixtures of copper powder and bare SIC whiskers.