The aim of this work was to study the tribological benefits of PIII treated austenitic stainless steel by nitrogen ions and/or C ions in a ringer solution, which simulates the environment of the human body. This was achieved by hardness, wear and friction testing, and atomic force microscopy and XRD studies. The results showed that the samples, both treated and untreated, exhibited virtually no wear from contact with the ultra high molecular weight polyethylene (UHMWPE) pins, however, the pins themselves exhibited wear. The amount of wear of the pins was found to decrease with increasing PIII treatment temperature, but addition of C to the chamber caused some increase the amount of wear on the pins. Although C ions reduced to improve the hardness, friction characteristic was improved by formation of carbon-expanded austenite. (c) 2005 Elsevier B.V. All rights reserved.