The kinetics of the hydrodesulphurization of thiophene dissolved in benzene have been studied over a commercial cobalt molybdenum catalyst in a fixed bed reactor at atmospheric pressure and temperatures of 320-390-degrees-C. Partial pressures of reactant species were varied in the range of 2.12 x 10(-3)-5.03 x 10(-3) and 0.682-0.886 atm for thiophene and H-2, respectively. Rate equations of the Langmuir-Hinshelwood type have been compared with the rate data using a non-linear least-squares regression technique.