The speed of sound and density of 1-phenyl-ethanone, 1-phenyl-propan-1-one, 1-p-tolyl-ethanone, and 1-(4-chloro-phenyl)-ethanone with N-methyl-acetamide, over the entire range of composition, have been measured at a temperature of 308.15 K. From the above experimental data, values of deviations in the speed of sound and isentropic compressibility have been calculated. The results are fitted to the Redlich−Kister polynomial equation of the third degree to derive the binary coefficients and standard deviations. Furthermore, the experimental results are used to study the nature of the binary interactions in these mixtures.