With the increase in environmental awareness, disposal of any form of hazardous waste has become a great threat to the industrial sector. During desulphurization of petroleum product, there is generation of a huge quantity of hydro-refining spent catalyst. This catalyst consists of an appreciable amount of molybdenum metal and sulphur as well. When disposed to the environment, it pollutes the air as well as ground water levels. Keeping in view the above, lime-enhanced carbothermic reduction has been proposed to be carried out for this spent catalyst. The effect of various experimental parameters on the recovery of molybdenum has been discussed in this article. (C) 2004 Elsevier B.V. All rights reserved.