The attenuation of thermally induced sound waves in neat pyridine has been measured by Brillouin light scattering. Frequency shifts and Brillouin line widths are obtained as a function of temperature from 296 to 354 K. The spectra are analyzed in terms of an extended hydrodynamic light scattering theory which includes the effect of orientational anisotropy on the polarized Rayleigh-Brillouin spectra. Various contributions to the Brillouin line width are calculated. The bulk viscosity of neat pyridine is significantly greater than the shear viscosity. The dispersion in pyridine is due to translation-vibration energy transfer. The nature of the vibrational relaxation process in pyridine is probed.