The CuFe1-xCrxO2 (0 <= x <= 1) delafossite solid solution was prepared by a standard solid-state reaction. These oxides crystallize with the delafossite structure. Their thermostructural properties were studied by thermogravimetric analysis and high-temperature X-ray diffraction experiments under an air atmosphere up to 1000 degrees C, For x = 0, CuFeO2 is oxidized into the spinel (CuFe2O4) and CuO phases, whereas for x = 1, CuCrO2 is thermally stable. For all of the intermediate compositions (0 < x < 1), complex oxidation, reduction, and phase transitions between delafossite and spinel have been observed.