The hardness behavior was compared for five prosthetics/orthotics polymers : Durr-Plex (copolyester), Polypropylene (polypropylene), Subortholen (polyethylene), Surlyn (ionomer), and Uvex (and cellulose acetate butyrate). The hardness is related to a number of factors including the composition and condition of the polymers. The polymers were examined in the as-received and simulated clinical fabrication heat-treated conditions. The simulated clinical fabrication heat-treated specimens were subsequently treated to 2 weeks, 4 weeks, and 8 weeks of artificial weathering conditions, consisting of exposure to cycles of ultraviolet light and heated condensation. Five measurements were taken for each treatment condition using a Durometer hardness tester. The hardness ranges and the respective rankings for the polymers were determined. Analysis of variance (ANOVA) and post hoc Scheffe statistical analyses were performed for different polymers of the same treatment condition, and different treatment conditions of the same polymer. The analysis of variance (ANOVA) showed significant hardness differences for the five polymers. The choice of material significantly influences the mechanical property of hardness for prosthetics/orthotics polymers. The Durr-Plex polymer had the highest hardness and the Surlyn polymer had the lowest hardness. The ranking trend was Durr-Plex > Uvex > polypropylene > Subortholen > Surlyn.