Excess molar enthalpies, H-m(E) of binary mixtures of anisole + glycols and polyglycols were measured by a flow microcalorimeter at 308.15 K and at atmospheric pressure over the whole composition range. Binary mixtures contained anisole+ diethylene glycol, anisole + triethylene glycol, anisole + tetraethylene glycol, anisole + poly(ethylene glycol)-200, anisole + poly(ethylene glycol)-300, anisole + poly(ethylene glycol)-400, anisole +poly(ethylene glycol)-600. Effects of the molecular weight distribution (MWD), of the polymer were investigated too, by preparing three additional samples of poly(ethylene glycol) (PEG) with the same number average molecular weight (M-n approximate to 300), but different MWD. Values of H-m(E) of the corresponding binary mixtures with anisole were measured. For all mixtures, results were fitted to the Redlich-Kister polynomial. H-m(E) curves are asymmetrical, showing positive deviations for mixtures containing glycols and poly(ethylene glycol)-200, negative C, vary from a maximum deviations for poly(ethylene glycol)-600, and an inversion of sign in the other cases. Values of H-m(E) of 440 J mol(-1) (anisole + triethylene glycol) to a minimum of -390 J mol(-1) (anisole + poly(ethylene glycol)-600). Effects of changes in the glycols chain length and in MWD on the molecular interactions between the mixture components are discussed. (C) 2003 Elsevier B.V. All rights reserved.