This study comprises the effect of particle size and heating rate on the pyrolysis of Silopi, Turkey asphaltite by non-isothermal thermogravimetry. The TG/DTG experiments were performed at five different heating rates with three different size fractions from ambient up to 900 degreesC in nitrogen atmosphere. The pyrolysis characteristics of the samples were analyzed using TG/DTG curves. Also, the pyrolysis kinetics of the samples were determined using the Arrhenius type kinetic model and ASTM methods. Results showed that there are significant differences in the pyrolysis characteristics and kinetics of the samples according to different size fractions and heating rates. (C) 2003 Elsevier Science B.V. All rights reserved.