An atomic force microscope (AFM) was used to determine the nanotribological properties of poly(ether ketone ketone) (PEKK) and sulfonated poly(ether ketone ketone) (S-PEKK) thin films, by sliding the AFM tip on the polymer surfaces and stepwise increasing the loading forces on the cantilever. For comparison, a polystyrene (PS) film with surface roughness comparable to those of the PEKK and S-PEKK was also examined using the same procedure. It was found that the S-PEKK film exhibits much higher values of both the coefficient of friction and the adhesive force than the PEKK film, which exhibits slightly higher values than the PS film. The surface topographies of the polymer films captured after frictional measurements suggest that PEKK has much better wear resistance than PS, whereas S-PEKK displays some visco-elastic character.