<p>The invention relates to an acid-dyeable polyamide fiber which can be obtained very reproducibly and unsusceptibly to faults during the production process. The fiber is characterized in that the amino end group content is less than 10 meq/kg. A very reproducible affinity for dyestuffs is obtained by copolymerization of a compound containing an acidic end group and having a basic nature. Compounds derived from melamine are particularly suitable.</p>
