Densities and viscosities of binary mixtures of N,N-dimethylformamide (DMF) with aniline and benzonitrile have been measured at (298.15, 303.15, 308.15, and 313.15) K. From these data, excess molar volumes (V-E) and deviations in viscosity (Deltaeta) have been calculated. Negative excess molar volumes and negative deviations in viscosity for DMF + aniline systems are attributed to the interstitial accommodation of DMF molecules into clusters of aniline. Negative excess molar volumes and positive deviations in viscosity for DMF + benzonitrile systems are due to the strong specific interactions. The excess molar volumes and deviations in viscosity are fitted to the Redlich-Mster polynomial equation.