Abstract: The object of the invention are adhesion promoters for plastisols of polyvinylchloride polymers or copolymers, characterized in that they are constituted by polyaminoamidic resins obtained by means of the condensation of:1 equivalent of carboxylic acids, obtained by polymerization of unsaturated fatty acids, of composition comprised within the following ranges: 0-2% monomers, 10-50% dimers, 50-90% trimers, withfrom 1.0 to 2.2 equivalents of an heterocyclic amine of general formula ##STR1## wherein R can be H or an alkylamino group --R'--NH.sub.2, wherein R' is a saturated alifatic chain.