Pyrolysis of three different types of solid wastes - willow cultivated on heavy metal polluted areas, furniture waste, municipal wastes of city Lodz was investigated by means of thermogravimetry. The experiments were carried out in the temperature range of 30-1000 degrees C under the inert gas milieu at three different heating rates beta (5, 10 and 20 degrees C/min). Utilising the methods of thermogravimetric analysis (TGA) the kinetic parameters (pre-exponential factors and activation energies) of the thermal decomposition of the solid wastes were determined.