Relative permittivities (epsilon) at five temperatures, between (293.15 and 313.15) K, viscosities (eta) at three temperatures, between (293.15 and 303.15) K, and speeds of sound (u) at 298.15 K of binary mixtures of 2-methoxyethanol (1) + butylamine (2) are reported. From all those data, the deviations from mole fraction additivity of the relative permittivity (Deltaepsilon), viscosity (Deltaeta), and speed of sound (Deltau) were calculated and fitted to a Redlich-Kister equation.