The present paper reports study of dielectric & physicochemical properties like dielectric constant, viscosity, density and refractive index for the binary mixtures of Nitromethane (NM) and Dimethylsulphoxide (DMSO) over the entire concentration range were measured at 293.15K. The experimental data further used to determine the Bruggeman factor, and excess properties viz. excess density, excess viscosity, and excess refractive index. The values of excess properties further fitted with Redlich–Kister equation. Excess properties were used to indicate the presence of intermolecular interactions and strength of intermolecular interactions between the molecules in the binary mixtures.