Here we present a new method for improving adhesion between natural rubber (NR) and polyester fabric. This is done by in situ grafting of maleic anhydride ( MA) onto NR in a two-roll mill. The grafting procedure was followed by infrared spectroscopy (FT-IR). The effect of ultraviolet/ ozone (UV/O(3)) radiation on the stability of the rubber mix as well as on the peel strength of the rubber coated fabric was investigated. Mechanical and spectroscopic analyses as well as light microscopy were used to assess the adhesion properties of the resultant rubber mixes to the polyester fabric. It was observed that the grafting with MA together with UV/O(3) treatment improved the peel strength of the rubber coated polyester fabric. (C) Koninklijke Brill NV, Leiden, 2009