Densities of the binary systems of benzene with ethyl acrylate, butyl acrylate, methyl methacrylate, and styrene have been measured as a function of the composition, at 298.15 K and atmospheric pressure, using an Anton Paar model DMA 5000 oscillating U-tube densitometer. The calculated excess volumes were correlated with the Redlich-Kister equation and with a series of Legendre polynomials. The excess volumes are positive for all the systems reported here.