Diamond nucleation and deposition on Ti6Al4V substrates were investigated using microwave plasma assisted chemical vapor deposition under different seeding and deposition conditions. The samples prepared were characterized by scanning electron microscopy and Raman spectroscopy. The results show that the nucleation density of diamond can be enhanced up to 10(11)/cm(2) by nanodiamond seeding and two-step deposition. By optimizing the seeding and deposition parameters, nanocrystalline diamond thin films were synthesized at relatively low microwave power (600 W) within a short time deposition; consequently, the microstructure change of Ti6Al4V as a result of hydrogen diffusion was significantly reduced due to the low deposition temperature and short deposition time. (C) 2012 Elsevier B. V. All rights reserved.