The possibility of dissolving poly(ethylene oxide) [PEO:H-(O-CH2-CH2)(n)-OH] in its monomeric liquid ethylene glycol [EG:H-(O-CH2-CH2)-OH] represents the only way to verify the complex polymer-monomer interactions, through the OH end groups, resulting in the scaling law R proportional to N-nu. We report viscosity results, in conjunction with photon correlation spectroscopy data, on different molecular weight PEO samples, in a wide range of concentrations, dissolved in EG. In order to distinguish among various interaction mechanisms, we also studied PEO dissolved in EG monomethyl ether [EGmE:CH3-(O-CH2-CH2)-OH] and EG dimethyl ether [EGdE:CH3-(O-CH2-CH2)OCH3], the latter not having in its chemical structure OH hydroxylic groups available to give rise to hydrogen bond interactions. In particular, the quality (good-theta-poor) of the solvents has been analyzed by verifying the well-known Mark-Houwink-Sakurada scaling law and the effects of the polymer-solvent interactions on the coils diffusive properties. (C) 2000 American Institute of Physics. [S0021-9606(00)51509-8].