The suitability of a combination of an infrared spectral search program and three commercially available infrared spectral data bases to structurally identify prosthetics/orthotics polymers was assessed. Five currently used prosthetics/orthotics polymers subjected to a simulated clinical fabrication heat treatment were examined using diffuse reflectance. The polymers selected were Durr-Plex (polyethylene terephthalate), polypropylene, Subortholen (polyethylene), Surlyn (ethylene methacrylate ionomer), and Uvex (cellulose acetate butyrate). The combination of a spectral search program and three commercially available data bases was inadequate for structural identification of these prosthetics/orthotics polymers in their simulated clinical fabrication heat-treated condition and may be misleading. Benefits of creating effective combinations of spectral search software and appropriate and more comprehensive data bases with specific entries for prosthetics/orthotics polymers would be for : (1) quality control of batches of polymers, and (2) the development of standards, test methods necessary to evaluate the effects of environmental influences associated with long-term clinical service.