The effects of molecular weight and polymer flux were studied during the adsorption of poly(ethylene oxide) onto planar surfaces that are physically heterogeneous but chemically homogeneous. Substrates that differed only in the degree of roughness were prepared by thermal evaporation of gold on glass and by template stripping of gold from mica. Chemical homogeneity was ensured by modification with a self-assembled monolayer dodecanethiol [CH3(CH2)(11)SH]. Kinetic studies revealed that, for polymers with molecular weights between 9.9 and 624 kDa, the initial rate of adsorption was lower on smooth substrates than the rate on rough substrates. The difference in rates could be suppressed by increasing the polymer flux via a change in either bulk concentration of the polymer or the convective transport coefficient, On rough surfaces, the initial rate of adsorption was found to be proportional to MW-0.3, which is close to the scaling MW-0.33 expected for transport-limited adsorption. On smooth substrates this dependence changed to MW-0.46 indicating an additional molecular weight dependence from interactions associated with the surface.