A series of new complexes formed by the interaction of cobalt(II) with doxepin hydrochloride (DOX) have been isolated and characterized by elemental analysis, and electronic, IR, magnetic moment and conductivity measurements. Based on the spectral data, an octahedral structure is suggested for the metal complexes. Thermogravimetric (TG) studies of the complexes have been performed in order to establish the mode of their thermal degradation. The thermal degradation was found to proceed in three steps. The kinetics and thermodynamic parameters were computed from the thermal decomposition data. The activation energy of the thermal degradation process is in the range 11.8-172 kJ mol(-1).