Dielectric spectroscopy was applied to study the molecular dynamics of a nematic main-chain liquid crystalline polyester using a Du Pont Dielectric Analyser. The dielectric measurements covered a frequency range from 0.03 to 100000Hz and a temperature range from -100 to 160 degrees C leading from the transition region up to the isotropic fluid region. Dielectricrelaxation processes alpha,beta,gamma and delta were observed and analysed. Apparent activation energies of the processes were calculated.