The synthesis, IR-spectra and thermal analysis of tetrahedral or octahedral Cd(II)-complexes of 3(5)-amino-5(3)-methylpyrazole (L), as represented by the general formula CdX2L2. nH(2)O (X= CS-, NCO-, Cl-, n=2; 1/2 SO42-, n=l), and of the complex Cd(OAc)(2)L-3. H2O are described. Thermal decomposition of the acetato complex results in an intermediate, appearing in the 480-580 K range. On the basis of the IR-spectrum and the results of elemental analysis of the intermediate, a decomposition scheme is proposed. Because of the involvement of a different anion, the thermal decomposition of the other complexes differs from that of the acetato complex.