New composite materials were fabricated by the incorporation of nanodiamond into plated films. The nanodiamond content in the films was found to saturateat around 2% as the concentration in the bath was increased. It was found that a strong interaction must be induced between the nanodiamond and the deposition frontier in order to incorporate larger concentrations into the films. A content of 5.6% was achieved by the addition of surfactants and brighteners to the baths. Refinement of the nanodiamond by boiling sulfuric acid with nitrate ions was found to be necessary to achieve good reproducibility. The films with 5.6% nanodiamond content were also produced using iodide ions for the refined nanodiamond. In addition, a Ni-P-nanodiamond composite film with a 14% nanodiamond content was successfully fabricated from a bath that contained only citrate as a complexing agent. Finally, the co-deposition mechanism of nanodiamond in plated films was identified. A very low friction coefficient of 0.03-0.04 was achieved for Ni-W-P-nanodiamond plated films.