A kinetic study of the pyrolysis of municipal solid waste (MSW) was carried out by thermogravimetric analysis (TGA). Different runs were performed at heating rates between 1.5 and 200 degrees C min(-1). A correlation model that considers two independent reactions was applied to simulate the process. The values of the kinetic parameters were optimised and compared with the results obtained from the correlation of the experiments carried out in a Pyroprobe 1000, where the nominal heating rate was 20 000 degrees C s(-1). Tn view of the results obtained, a theoretical analysis was developed with reference to the influence of the heating rate and the heat transfer on the kinetic parameters that can be obtained from the experimental data.