In this work, a series of thermophysical properties (apparent specific volume, excess molar volume, excess Gibbs energy of activation for viscous flow, coefficient of thermal expansion, excess coefficient of thermal expansion) of poly (ethylene glycol) 600 (PEG600) + methanol, ethanol, 1-propanol, and 2-propanol binary liquid mixtures were determined based on density and viscosity experimental measures at 293.15 K, 298.15 K, and 303.15 K and refractive indices at 298.15 K. After that, the obtained excess parameters were used to analyze the inter-intra molecular interactions in the liquid mixtures. In order to estimate the interaction parameters, the excess molar volume results were fitted to Redlich–Kister polynomial. Moreover, a set of semi-empirical relations were proposed to predict the viscosity of liquid mixtures.