Nano-structured hydrogen titanate and sodium hydrogen titanate layers were formed when Ti metal was treated with H 2 O 2 and NaOH solutions, respectively. The chemically treated Ti metals upon subsequent treatment with Ca(NO 3 ) 2 and CaCl 2 solutions, resulted in incorporation of Ca 2+ ions into the nano-structured titanate layer. Thus formed nano-structured titanate layers containing Ca 2+ ions when subjected to heat treatment, forms anatase and calcium titanate-rutile phases, respectively. In vitro apatite-forming ability in simulated body fluid (SBF) was positive for H 2 O 2 -Ca and heat-treated Ti metal in contrast to NaOH-Ca and heat treatment. Formation of anatase phase together with Ca 2+ ion release into SBF was found to be the key driving force for such a high bioactivity of Ca 2+ containing H 2 O 2 treated Ti metal on contrary to NaOH and heat treatment. This study provides a new insight into the factors accelerating the bioactivity of Ti metals during various chemical and thermal treatments, which further aid and abet to design dental and orthopaedic implants with high bone-bonding ability. © 2019 Elsevier B.V.