A thermoanalytical study of 4(5)-hydroxymethyl-5(4)-methylimidazole complexes with divalent cobalt, nickel and copper, with a general formula ML4(NO3)(2) is reported: the thermal stability and the decomposition steps were determined by thermogravimetry (TG) and derivative thermogravimetry (DTG). The released products, due to the thermal decomposition, were analyzed by on-line coupling a FT-IR spectrometer to the thermobalance; the so obtained evolved gas analysis (EGA) allowed to prove the proposed decomposition steps. The decomposition kinetics was examined by using the Flynn-Wall-Ozawa and Kissinger methods. From the former method the E dependencies were presented and connected with the corresponding steps mass loss; from the latter method the activation energies and the pre-exponential factor were computed. (C) 2004 Elsevier B.V. All rights reserved.