Chicken feathers (CFs), waste from the poultry industry, were tested as biosorbent for colour removal of synthetic coloured water. Biosorption kinetics and isotherms were determined to provide an explanation to the physicochemical behaviour of the biosorption process of C.I. Acid Blue 80 dye on CFs. Up to 80% of the dye was biosorbed at 50°C demonstrating the biosorbent potential of the waste for the removal of organic dyes. Moreover, two mathematical approaches have been used to estimate the thermodynamic parameters such as the enthalpy, the entropy and the affinity of sorption. The first approach uses the Langmuir equation (affinity of sorption of 27,514 J/mol at 50°C) whereas the second approach calculates the affinity directly using the chemical potentials. In both cases, the affinity of the system is positive indicating that the biosorption process occurs spontaneously. In addition, the infrared spectroscopy and scanning electron microscopy results shown that the chemical structure and the morphology of the fibres were not significantly affected by the biosorption step