The surface segregation behavior of poly(dimethylsiloxane)/polyethylene (PDMS/PE) and poly(dimethylsiloxane)/polypropylene (PDMS/PP) blends has been studied using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). It is shown that the overall concentration of silicon-containing species at the surface in these systems can be controlled by solvent washing, annealing, and plasma treatment. In the case of plasma oxidation, well-adhered SiOx coatings are produced.