Abstract: The invention relates to polyamino-amide hardeners for epoxy resins, the hardeners being the product resulting from the limination of at least one mole of water per acid equivalent from a mixture of:90 to 60 parts of at least one unsaturated monomeric fatty acid having at least 12 carbon atoms,10 to 40 parts of an acid having a molecular weight less than 20020 to 80 parts of a polyalkylene-polyamine, and80 to 20 parts of isophorone diamine, the relative proportions of all the acid products with respect to all the amine products being from 1 to 2 gramme equivalents of acid function per gramme molecule of amine.The invention also relates to a method of hardening epoxy resins using the above hardeners.