The reduction of p-nitrotoluene (PNT) by aqueous ammonium sulfide was carried out using a triphasic (liquid-liquid-solid) catalyst, anion exchange resin (AER). The maximum enhancement factor of about 57 was observed with 20% (w/v) loading of AER. The reaction was observed to be kinetically controlled with apparent activation energy of 49.8 kJ/mol. The rate of reduction of PNT was established to be proportional to the square of the concentration of sulfide and to the cube of the concentration of PNT. Based on the detailed kinetic study, an empirical kinetic model was developed to correlate the experimentally obtained conversion versus time data. The developed model predicted the PNT conversions reasonably well. (C) 2007 Elsevier B.V. All rights reserved.