The corrosion protection performance of electrodeposited Ni-P and Ni-P-C composite coatings on copper substrates was studied. The effect of heat treatment on the coatings performance was also studied. The investigated coatings performance has been evaluated on the basis of electrochemical data obtained from the potentiodynamic polarization Tafel curves and electrochemical impedance spectroscopy in 1 M NaOH solution at 298 K. The results showed that incorporation of carbon nanoparticles from L-lysine source into Ni-P matrix increased significantly corrosion resistance of the coating. Based on these investigations, it was found that the Ni-P-C composite coatings after thermal treatment in air at 673 K are more corrosion resistant in alkaline solution than the as-deposited coatings. (C) 2012 Elsevier Ltd. All rights reserved.