The experimental densities of binary mixtures of cyclopentanone with 1,1,2,2-tetrachloroethane, 1,1,1-trichloroethane, trichloromethane, 1,2-dichloroethane, 1,3-dichloropropane, 1,4-dichlorobutane, and 1-chlorobutane have been measured at T = (288.15, 298.15, 308.15, and 318.15) K,and atmospheric pressure, over the whole composition range. From these results, excess molar volumes, V(E), have been calculated and fitted to the Redlich-Kister polynomial equation. The excess molar volumes are negative for the cyclopentanone + 1,1,2,2-tetrachloroethane, 1,1,1-trichloroethane, trichloromethane, and 1-chlorobutane systems and positive for the other three systems over almost the whole mole fraction range and temperatures studied. The variation of these properties with composition of the binary mixtures is discussed in terms of molecular interactions between components and structural effects.