Excess volumes, V-E, Of binary liquid mixtures of N,N-dimethylformamide with methyl propyl ketone, diethyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, and cyclohexanone at 303.15 K have been measured with a dilatometer. Excess volumes are negative for the systems N,N-dimethylformamide with methyl propyl ketone, diethyl ketone, methyl isobutyl ketone, and methyl isopropyl ketone and are positive for N,N-dimethylformamide with cyclohexanone at 303.15 K.