The thermal behaviour of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pd(II) complexes of uracil was studied by TG, DTG and DTA in a dynamic nitrogen atmosphere. Two processes occur in the isolated uracil complexes: dehydration and pyrolytic decomposition. In the hydrated complexes, the first stage observed was the loss of water molecules, which was followed by decomposition of the uracil. The thermal dehydration of the complexes occurred in from one to three steps. The final decomposition products were found to be the respective metal oxides, except in the cases of the Co(II) and Pd(II) complexes, which produced metallic cobalt and palladium, respectively. The order of reaction and energy of activation for the dehydration stage were evaluated.