The experimental densities, rho, relative permittivities, epsilon, and refractive indices, n(D), of binary mixtures of dihydrofuran-2(3H)-one + butan-1-ol and + butan-2-ol have been measured at T = (293.15 to 313.15) K and atmospheric pressure over the whole mole fraction range. From density data, excess molar volumes, V(E), were calculated at various temperatures. V(E) is negative for all systems investigated. The experimental results have been correlated using the Redlich-Kister polynomial equation, and parameters from least-squares analysis have been reported.