Abstract: The invention relates to a method for reducing the caprolactam content of polyamide 6 obtained especially by hydrolytic polymerization of epsilon-caprolactam. The method is characterized by the use of an additive that forms isocyanuric acid under the influence of heat. The additive or the isocyanuric acid produced externally under the influence of heat is added (a) to the polymerization or (b) to a melt of polyamide 6. This enables the caprolactam content of the polyamide 6 to be reduced considerably compared to that of usual commercial polyamide 6. In particular, the resulting polyamide 6 shows good characteristics for reprocessing e.g. into fiber and molding masses by melt extension.