Adhesive composition usable in particular as an adhesion primer, based on a polyisocyanate compound and a polyester or vinyl ester resin comprising (in particular hydroxyl) functional groups which are reactive towards isocyanate groups of said polyisocyanate, the total number of said isocyanate groups being in excess relative to the total number of said functional groups of the polyester or vinyl ester resin. The polyisocyanate compound is preferably a diisocyanate, the resin is preferably an epoxy vinyl ester resin, in particular novolac- and/or bisphenol-based. Said composition is usable, as an adhesion primer, in combination with a secondary adhesion layer preferably based on a polyvinylpyridine/stirene/butadiene elastomer and a polyester or vinyl ester resin. Use of such an adhesive system for bonding a cured polyurethane to an uncured diene elastomer composition, in particular in the manufacture of rubber articles consisting of ground contact systems for motor vehicles, in particular pneumatic or non-pneumatic tires.