The enthalpies of dissolution of NaCl in aqueous solutions of isomeric butanediols {1,2-butanediol (1,2BD), 2,3-butanediol (2,3BD), 1,3-butanediol (1,3BD), and 1,4-butanediol (1,4BD)} were measured within the whole available range of salt concentrations. The standard enthalpies of solution Delta(sol)H(m)(infinity) against the mixed solvent composition exhibit their maxima in the water-rich region of all the investigated mixtures. The positions and heights of the maxima depend on the kind of isomeric diol molecule. Enthalpic pair interaction coefficients h(xy) for (butanediol + NaCl) in water were calculated and analysed. In conclusion, it is suggested that interactions among the diol molecules influence their interactions with the investigated electrolyte.