The modifications induced by excimer laser radiation on different types of polymer surfaces (polyether-etherketone (PEEK), polycarbonate (PC) and epoxy resin) performed at laser fluences below the material ablation threshold have been investigated. Particular attention was given to the role of laser irradiation wavelength (193 or 248 nm) on the nature and properties of the treated surfaces. Results indicate that a much stronger reactivity was obtained after treatments at 193 nm for all the investigated polymers. At this wavelength, the original polymer surfaces are strongly modified by UV photons; surface reorganization occurs and polar groups induce an increase in the surface wettability.