Polymer films of poly(ethylene terephthalate), polypropylene, and cellophane were surface treated with tetrafluoromethane plasma under different time, power, and pressure conditions. Contact angles for water and methylene iodide and surface energy were analyzed with a dynamic contact angle analyzer. The stability of the treated surfaces was investigated by washing them with water or acetone, followed by contact angle measurements. The plasma treatments decreased the surface energies to 2-20 mJ/m(2) and consequently enhanced the hydrophobicity and oleophobicity of the materials. The treated surfaces were only moderately affected after washing with water and acetone, indicating stable surface treatments. The chemical composition of the material surfaces was analyzed with X-ray photoelectron spectroscopy (XPS) and revealed the incorporation of about 35-60 atomic % fluorine atoms in the surfaces after the treatments. The relative chemical composition of the C Is spectra’s showed the incorporation of -CHF- groups and highly nonpolar -CF2- and -CF3 groups in the surfaces and also -(C) under bar H-2-CF2- groups in the surface of polypropylene. The hydrophobicity and oleophobicity improved with increased content of nonpolar -CF2-, -CF3, and -(C) under bar H-2-CF2- groups in the surfaces. For polyester and polypropylene, all major changes in chemical composition, advancing contact angle, and surface energy are attained after plasma treatment for one minute, while longer treatment time is required for cellophane.