The 2,4,6-tris(dimethylaminomethyl)phenol shows a partial miscibility with water. The temperatures of liquid–liquid phase separation were experimentaly determined to establish the phase diagram. The specific heat capacities and densities of aqueous solutions of 2,4,6-tris(dimethylaminomethyl)phenol were measured to determine excess heat capacities and excess molar volume. Experiments have been carried out for temperatures range from 288 K to 338 K, at atmospheric pressure. The NRTL model was used to correlate liquid–liquid equilibria and, the UNIQUAC model to correlate heat capacities and predict excess molar enthalpies. The excess molar volumes were fitted to a Redlich–Kister polynomial.