The excess isentropic compressibilities, K-s(E) for seven binary mixtures of methyl methacrylate + benzene, +o-xylene, +m-xylene, +p-xylene, +toluene, +ethylbenzene and +cyclohexane were estimated from the measured densities and speeds of sound at 298.15 and 308.15 K. The K-s(E) values were large and positive for MMA + cyclohexane and +m-xylene, while they were negative for other mixtures. A qualitative analysis of K-s(E) values was made in terms of molecular interactions. The speeds of sound of all the mixtures were also predicted from the free length theory (FLT) and collision factor theory (CFT).