Abstract In this paper selected literature and experiments performed at the University of Illinois pertaining to the potential use of plasma-sprayed ceramic-coated metal systems as implant materials are reviewed. The nature of the coating-substrate bond is discussed. Adhesive and/or cohesive failure with regard to alumina-coated type 316L stainless steel and Ti-6Al-4V ELI substrates in physiological media is treated as a rate process. The issue of biocompatibility is addressed. Strategies for overcoming the problems uncovered are indicated.