This study investigated the effects of a nanoscale multi-layered structure on the hardness and thermal stability of Ti-Al-B-N coating. Bilayer period of nanoscale multi-layered TiAlN/BN coating, prepared by alternating deposition of TiAlN and BN layers, was controlled by changing BN target power. The hardness value of RAIN coating increased through nanoscale multi-layered structurization with a thin (similar to 0.6 nm) BN phase. The intensity of low angle XRD peaks and hardness of the nanoscale multi-layered TiAlN/BN coatings increased after heat-treatment in an N-2 atmosphere. The nanoscale multi-layered TiAlN/BN coating showed better thermal stability than that of TiAlN coating. (c) 2007 Elsevier B.V. All rights reserved.