Ti-implants plasma-sprayed with a hydroxyapatite (HA) coating are widely used. When using an implant the coating quality is characterized by the presence of HA decomposition products and sprayed material structure. This paper investigates the properties of hydroxyapatite coatings and their dependence on the types of plasma spray. The types of hydroxyapatite decomposition on titanium substrates using plasma spray technology are optimized. Paper includes a German-language abstract.