Polyurethane is a biocompatible material and its use is increasing as human or animal implants. However, problems due to wear debris and their interaction with the host require a better understanding of wear mechanisms and the genesis of the debris formation. Some effects of the contact pressure and geometry were experimentally investigated to identify the response, obtained by contact temperature, mass variation, Scanning Electron Microscopy and EDS microanalysis, of polyurethane samples from sliding against metallic surfaces.