Chemical vapor deposition (CVD) phase diagrams for the preparation of iridium films were calculated using Gibbs free energy minimization method. Iridium acetylacetonate (Ir(acac) 3 ) was used as the precursor compound. Two gaseous mixtures were analyzed: Ir(acac) 3 -O 2 -Ar and Ir(acac) 3 -Ar. The deposition temperatures were explored from 300 to 800 °C, total pressures from 13.3 to 13.332 Pa and partial pressures of Ir(acac) 3 gas and O 2 gas from 0.001 to 1.000 Pa. The Ir-CVD diagrams predicted that without Oj gas in the gaseous mixture, the solid films consist of two solid phases: Ir+C. In contrast, with addition of O 2 to the gaseous mixture, the Ir-CVD diagrams revealed different domains of condensed phases which include IrO 2 , IrO 2 +Ir, Ir and Ir+C. These diagrams allow one to establish the total pressures and temperatures required to obtain a given film composition. The results predicted by the Ir-CVD diagrams are in good agreement with those experimentally obtained.