Chicken feathers (CFs), mainly discarded nowadays, are an alternative reinforcement to be applied in the preparation of composite materials (CMs). The effect of different sanitizing methods on the properties of both CFs and the corresponding CMs has been studied. Some characteristic parameters such as density have been found to be dependent on the treatment that CFs endure, whereas the mechanical properties of the CMs made of thermoplastics matrices (e.g. polypropylene and high density polyethylene) were only slightly affected by the treatment. The introduction of CFs decreased the tensile strength of the CMs compared with the neat polymers while other parameters (e.g. Young’s modulus) were essentially unaffected