Conductance values of nimesulide have been determined in water in 0.1, 0.2, 0.4, 0.6, 0.8, 1 and 2 mol dm-3 aqueous solutions of hydrotropic agents (sodium benzoate, sodium salicylate, sodium bromide and nicotinamide) at temperatures 298.15, 303.15, 308.15 and 313.15 K. The conductance values have been used to evaluate the limiting molar conductance and association constants by means of Shedlovsky extrapolation technique. Thermodynamic parameters for the association process of nimesulide in aqueous solutions of hydrotropic agents have also been calculated.