The thermoanalytical study of some MeHm(x) complexes (Hm = histamine; x = 1, 2) and MeHm(x)(NO3)(2) (x = 2, 4) with Co-(II), Ni-(II) and Cu-(II) is reported. By TG-FTIR coupled analysis, the decomposition steps are analyzed and the intermediate reactions are proposed. Results of ESCA analysis for all Ni-(II) compounds indicate correct atomic ratios between organic and inorganic nitrogen and are useful for determining metal coordination states.