Block copolymers containing poly(ethylene oxide) (PEO) have a wide applicability within biomedical applications, not the least due to anti-fouling properties of surface coatings based on these copolymers. We have investigated a number of these, and results for PEO/poly(butylene oxide) (PEO/PBO), PEO/poly(lactide) (PEO/PL), and PEO/poly(ethylene imine) (PEO/PEI) copolymers, as well as for PEO-esterified fatty acids, are presented and discussed. For the former class of polymers, the effects of molecular architecture on the adsorption properties are adressed, and experimental results obtained with ellipsometry and small-angle neutron scattering presented. For the PEO/PL block copolymers, the effects of the PEO and PL lengths for the polymer adsorption are adressed, as are the effects of degradation of the PL moiety on both adsorption and protein rejection. For the PEO-esterified fatty acids, the effects of PEO chain length and interfacial density on the protein rejection capacity of such coatings are discussed.