The thermal studies of acetylacetonato aniline acetohydrazone and its divalent metal ions Mn2+, Co2+. Ni2+ and Cu2+ complexes were studied and discussed in terms of its molecular structure and type of metal ions. TG curves display mostly three steps of thermal decomposition. The first step is due to dehydration followed by the elimination of the anions from the complexes. The anhydrous free anion complexes undergo further decomposition forming metal oxides as final products. The activation energies E-a were evaluated and discussed in accordance with the structure of the complexes, which was assured, by elemental analyses and IR spectra. (C) 2010 Elsevier B.V. All rights reserved.