Seven pairs of clino and orthopyroxenes from granulites belonging to the Paraíba do Sul belt (Atlantic granulite belt) have been chemically analysed by electron microprobe method.Thermodynamic equilibrium among coexisting pyroxenes is evident from the textural patterns; distribution coefficient for Fe-Mg and the crystallization trends. Geothermometric calculations indicate temperatures of about 850°C for the equilibration of the minerals. These values point to the formation of the Paraíba do Sul pyroxenes under high grade metamorphic conditions.Seven pairs of clino and orthopyroxenes from granulites belonging to the Paraíba do Sul belt (Atlantic granulite belt) have been chemically analysed by electron microprobe method. Thermodynamic equilibrium among coexisting pyroxenes is evident from the textural patterns; distribution coefficient for Fe-Mg and the crystallization trends. Geothermometric calculations indicate temperatures of about 850°C for the equilibration of the minerals. These values point to the formation of the Paraíba do Sul pyroxenes under high grade metamorphic conditions.