A kinetic study of the combustion of a varnish waste based on polyurethane was carried out by thermogravimetric analysis (TGA). Different runs were performed at heating rates between 5 and 20 degreesC min(-1) and oxidizing atmospheres with a percentage of oxygen between 10 and 33.3% (v/v). A correlation model that considers four reactions: pyrolysis of solid, oxidation of the solid, and combustion of the residues generated in both previous reactions was applied to simulate the process. The model proposed satisfactorily fits the available experimental data.