o-Xylene is nitrated in liquid phase with high regio-selectivity using beta zeolite as a catalyst with stoichiometric quantity of nitric acid. The use of acetic anhydride is completely eliminated with almost zero emission of effluents. There is no formation of oxygenates or side chain nitration. The influence of experimental conditions like effect of solvent, rate of addition of nitric acid, effect Of SiO2/Al2O3 ratios, are also investigated. The process is eco-friendly and less expensive and represents a clean synthesis of nitro aromatic compounds with higher regio-selectivity. (C) 2004 Elsevier B.V. All rights reserved.