Effect of molybdenum disulfide dispersity and friction test conditions on wear rate of its 1%-filled PTFE-based composites is studied. It is found that under certain test conditions the wear rates of the composites filled with sub micro- or nanosized filler are similar to reported values for the PTFE composites filled with 20mass%–30vol% of microsized MoS 2 . It is attributed to accumulation of the highly dispersed filler particles producing discrete MoS 2 coatings over parts of the friction surface.Results of IR-spectroscopic study of the friction layer polymer show that PTFE macromolecules undergo tribochemical processes of hydrolytic degradation comprising main chain scission, defluorination, hydrogenation and hydroxylation presumably catalyzed by highly dispersed MoS 2 at higher friction temperature, which may additionally enhance the composites׳ wear resistance.