To construct biocompatible surfaces of polypropylene (PP), poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) was melt-grafted onto PP backbones; this was followed by the restructuring of the surface mircostructure of the grafted PP by water treatment. The grafted products were analyzed by Fourier transform infrared spectroscopy and 1H-NMR; the surface microstructure of the graft copolymer was characterized by X-ray photoelectron spectroscopy and atomic force microscopy, and the biocompatibility was evaluated by water contact angle, protein adsorption, and platelet adhesion measurements. This study showed that highly biocompatible surfaces of PP could be obtained by a combination of melt grafting and surface restructuring techniques, and the formation of hole-with-rim patterns and the enrichment of the PEGMEMA chains on the topmost surface were the key factors for the improved biocompatibility. This work advances functionalized PP generated by melt grafting as a promising candidate for applications in blood-contact devices. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012