Experiments on the adsorption of PEO from aqueous solutions onto planar surfaces that are physically heterogeneous but chemically homogeneous are presented. Gold substrates that differ only in the degree of roughness were prepared by thermal evaporation on glass and by template stripping from mica. To ensure a similar chemical interface, the gold substrates were modified with a self-assembled monolayer of a long chain alkanethiol (CH3(CH2)(11)SH). The kinetics of adsorption of PEO were monitored using a surface plasmon resonance technique with high time resolution. The experimental measurements demonstrated that higher adsorbed amounts and lower chain distortion accompanied an increase in surface roughness. These are the first systematic experimental measurements that substantiate past theoretical predictions of polymer adsorption on random surfaces. Kinetic studies revealed that the initial rate of adsorption was proportional to bulk concentration on both rough and smooth substrates, but the PEO adsorbed more readily on the rougher surfaces.