Abstract: The present invention relates to an epichlorohydrin elastomer composition having an improved ageing resistance.This composition comprises 100 parts by weight of epichlorohydrin homopolymer or copolymer, 0.5 to 20 parts by weight of a plasticizer such as stearic acid, 1 to 150 parts by weight of a reinforcing filler constituted by a slightly agglomerated, medium structure carbon black having an average particle size of 200 to 280 microns and 0.5 to 7.5 parts by weight of a first acid acceptor constituted e.g. by zinc or calcium stearate, 0.5 to 7.5 parts by weight of a second acid acceptor constituted e.g. by lead oxide Pb.sub.3 O.sub.4, 0.5 to 5.5 parts by weight of at least one protection agent constituted by an organic compound with conjugated aromatic cycles containing amine or phenol functions and/or by an alkyl or aryl dithiocarbamate metal salt and 0.5 to 5.5 parts by weight of a vulcanizing agent preferably constituted by hexamethylene diamine carbamate.