The thermal decomposition of solid rhodium(II) acetate was studied by isothermal TG. Kinetic analysis of the isothermal data showed that the complex decomposition in the range 198.0-210.5 degrees C occurs according to a Prout-Tompkins (A(a)) law. The isothermal curves are better fitted using a non-linear least square method. The activation energy found was 162.7 kJ mol(-1). At temperatures higher than 210.5 degrees C the decomposition is strongly accelerated and no kinetic study was available.