The molar heat capacities of the (water + acetonitrile) mixtures have been measured at T = (283 15, 298.15, 313.15, and 328.15) K as a function of mole fraction. The excess molar heat capacities. C-p(E), limiting partial molar heat capacities of water and acetonitrile (C) over bar (p)degrees have been calculated The excess molar heat capacities are positive over the whole mole fraction range and increase with increasing temperatures from (283.15 to 328.15) K The excess molar heat capacities have been fitted to the Redlich-Kister equation (C) 2010 Elsevier Ltd All rights reserved