In this paper, (Ti1-xNbx)5Si3 nanocrystalline films were synthesized and their potential as highly corrosion-resistant coatings for the biomedical alloy Ti-6Al-4V was explored. To assess the electrochemical behavior of the as-deposited films, the samples were immersed in Ringer's solution open to air at 37 °C. The processes that govern the electrochemical reactions at the film surface were analyzed using a combination of complementary electrochemical measurement techniques such as potentiodynamic polarization, electrochemical impedance spectroscopy and Mott-Schottky analysis. The results show that the (Ti1-xNb x)5Si3 nanocrystalline films offer Ti-6Al-4V a strong shield from corrosive attack and the addition of Nb in the films greatly enhances their resistance to corrosion, and in so doing, minimizes metal ion release. Collectively, our data suggest that (Ti1-xNb x)5Si3 nanocrystalline films as supreme coatings with anti-corrosive properties have potential to improve the performance and extend the service life of orthopedic and cochlear implants. © 2013 Acta Materialia Inc.