Polydimethylsiloxane (PDMS) has been extensively used in microfluidic, coating, and biomedical applications. It is desirable, however, to improve the biocompatibility and clinical performance of PDMS by increasing the hydrophilicity of the surface. In this study, we fabricate PDMS films with dextran and polyethylene glycol (PEG) covalently bound to the surface and correlate changes in protein adsorption with relevant surface properties such as morphology, wetting, and surface charge. PDMS films are functionalized in a microwave oxygen plasma to form hydroxyl groups and aminated by incubation in a (3-aminopropyl)trimethoxysilane (APTES) solution. Oxidized dextran and PEG-aldehyde are then covalently bonded to the surface amines via reductive amination. The films are characterized by contact angle, zeta potential, tapping mode atomic force microscopy (AFM) imaging, and AFM force curves. Fluorescent microscopy is used to quantify the amount of labeled bovine serum albumin and fibrinogen adsorbed to the surface.