Thermogravimetric (TG) and derivative thermogravimetric (DTG) investigations of p-toluidino-p-chlorophenylglyoxime (p-T-p-CPG) and of some complexes (Co(II), Ni(II), and Cu(II)) in dynamic nitrogen atmosphere have been studied to determine their modes of decomposition. All the complexes showed similar TG behaviour. The mass losses in the main decomposition stage indicated conversion of the metal complexes to its oxide. A gas chromatography-mass spectrometry (GC-MS) combined system was used to identify the products during pyrolytic decompositions. The final products of the decompositions were identified by X-ray powder diffraction method. The kinetic parameters (energy, entropy of activation and pre-exponential factor) were calculated from the data of TG curves. (C) 2002 Elsevier Science B.V. All rights reserved.