The bend and splay elastic constants of MBBA were measured over its nematic temperature range. The ratio of the two constants is 1.25±0.05. The temperature dependence of the elastic constants is found to be adequately described by the simple mean-field models. A comparison is made between viscosity coefficients obtained from the elastic constants and light scattering spectra and from classical viscosity measurements. A method proposed for the measurement of twist elastic constants is evaluated and an upper limit of this constant of MBBA as a function of temperature is reported.