Densities and viscosities of binary liquid mixtures of formamide with 2-methoxyethanol, acetophenone, acetonitrile, 1,2-dimethoxyethane, and dimethylsulfoxide have been measured at (298.15, 308.15, and 318.15) K and over the entire composition range at p = 0.1 MPa. Ultrasonic speeds of these binary liquid mixtures have also been measured at 298.15 K and the same pressure. From the experimental data, values of excess molar volume V-m(E) , Viscosity deviation Delta eta, and deviation in isentropic compressibility Delta K-S have been determined. These results were fitted to the Redlich-Kister-type polynomial equation. The density and viscosity data have been analyzed in terms of some semiempirical viscosity models.