Here, we described a simple approach for the development of advanced composites based on Nylon 12 by selectively modified multiwalled carbon nanotubes (MWCNTs). Prior mixing, MWCNTs were modified by a new combination of plasma treatment i.e. oxygen + nitrogen (PL-MWCNTs) in order to improve its dispersion in the nylon matrix and enhance the interfacial adhesion by increasing the compatibility. With incorporation of only 1.2 wt % PL-MWCNTs, the tensile strength, Young's modulus, elongation at break and storage modulus of Nylon 12 were dramatically improved by similar to 66%, 64%, 69% and 39%, respectively. These results were found to be higher than individual plasma treated CNTs. Such large increments were due to the effects of excellent homogeneous dispersion of PL-MWCNTs in the Nylon matrix and strong interfacial adhesion within themselves, which is believed to be effects of both oxygenated and nitrogenated functional groups generated on the surface of CNTs during plasma treatment. (C) 2014 Elsevier Ltd. All rights reserved.