A B4C-Mo composite coating was fabricated using a vacuum plasma spray technique, and its wear behavior was compared with that of a pure B4C coating. The microstructure of the composite coating was much more homogeneous and compact as a result of the formation of a (B, Mo) C transition phase, which effectively improved the interface between B4C and Mo splats. For this reason, the wear resistance of the composite coating was much superior to that of the pure B4C coating. The distribution of nano-sized Mo in the composite coating might also contribute to the improved tribological properties.