The thermal decomposition of an industrial sludge under nitrogen atmosphere was studied by means of thermogravimetric analysis (TGA) using the Shimadzu TG50 thermal analyzer. The TGA curves showed that the pyrolysis of dry sludge occurred in two stages, depending on the heating r ate. The first stage occurred between 315°C and 400 °C; the second stage, between 380 °C and 520 °C. Heating rates of 10, 20, 50 and 75 °C/min were employed in the study. The kinetics of the pyrolysis were deduced from the weight-loss versus temperature data. Two models were used to determine the kinetic parameters: the Simple Arrhenius Equation and the Coats & Redfern Model. The Simple Arrhenius Equation showed that at lower heating rates of 10 °C/min to 20 °C/min, the thermal decomposition of sludge was first-order but at higher heating rates of 50 °C/min to 75 °C/min, it was second-order. On the other hand, the Coats & Redfern Model indicated that the thermal decomposition of sludge was first-order at all heating rates from 10 °C/min to 75 °C/min. Results from the above-mentioned kinetic determination could be used in the proper design and operation of actual thermal processes for the disposal of industrial sludge.