Poly(dimethylsiloxane) (PDMS) substrates were modified with AB and ABA type block copolymers comprised of poly(ethylene oxide) (PEO) and PDMS segments by two methods: (1) the block copolymer was mixed in with the PDMS during polymerization; (2) the block copolymer was allowed to insert into solvent swollen PDMS monoliths. In both cases, van der Waals force and hydrophobic interactions between the PDMS monolith and PDMS segments in block copolymers were sufficient to lead to a stable hydrophilic surface. The surface fraction of PEO on the PDMS surface can be controlled by the cross-linking density of the PDMS matrix and concentration of PEO containing block copolymers used in modification procedure. Morphology of control and PEO tethered PDMS surfaces were investigated by Atomic Force Microscopy (AFM). The protein resistant properties of the PEO modified PDMS surfaces were investigated with fluorescence microscopy by measuring the adsorption of fluorescently labeled fibrinogen. The stability of the tethered PEO layer was verified by measuring advancing and receding contact angles on modified PDMS surfaces over the period of 30 days in PBS (pH 7.4) buffer.