Hyperbranched aminated collagen fibers were prepared by modifying collagen fibers with ethylenediamine. Cyanuric chloride was used as a crosslinking agent. Different generations of hyperbranched aminated collagen fibers were prepared by changing the molar ratio of ethylenediamine to cyanuric chloride. The structure of the first-generation fibers was characterized and analyzed via scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. The hyperbranched aminated collagen fibers were effective adsorbents for the removal of the acid black dye NT from aqueous solutions. The adsorption isotherm, as well as the kinetics of the first-generation hyperbranched aminated collagen fibers, was studied. The experimental results were fitted using the Langmuir and Freundlich equations. The findings indicate that the Freundlich isotherm is better in describing the adsorption process. Two kinetic models, the pseudo-first order and pseudo-second order, were used to analyze the kinetic data. The pseudo-second-order model was proven better in describing the adsorption behavior. (C) 2012 Elsevier B.V. All rights reserved.