Department of Chemistry, Jadavpur University, Calcutta-700 032 Manuscript received 14 December 1992 The hydration and solute—solvent interaction parameters of five polyethylene glycols PEG 200, 300, 400, 600 and 1000, have been reported. The hydration has been unambiguously evaluated using conductance and viscosity methods. A comparison of the important literature cited hydrations of EO group with the results of this study has been made. The viscosity B and C coefficients have been obtained from a quadratic fitting of relative viscosity with mol dm concentration of the PEG. The B coefficient has been analysed in the light of molecular size, solvation and water—structure modification. The solute—solute interaction parameter C has been observed to be significant for PEG 600 and 1000. The results are more consistent than that reported by Bahri and Guveli given in reference seventeen.