Performance of carbon black reinforced elastomers strongly depend on the adhesion at the filler-matrix interface. Surface characteristics of carbon blacks can be changed by use of a number of different techniques each with certain advantages and disadvantages and as regards to these, plasma surface modification is a novel one. This study aims to check the limits of applicability of plasma surface modification of carbon black to be used in the tire manufacturing industry. For this purpose, RF range cold plasma has been utilized in styrene or butadiene atmospheres. Tensile strengths and percent elongations of vulcanizates are found to respond differently if modified fillers are used as compared with those prepared by the unmodified fillers. Glass transition temperatures of vulcanizates are found to correlate well with the results of mechanical properties. Findings are also supported by the SEM pictures. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.