The phase transformations in Al-Cu-Fe cast alloys in the region of existence of the ico phase are characterized via X ray diffraction, X ray fluorescence, and scanning electron microscopy. It is established that the production of multiphase structures consists of a mixture of quasi crystalline and approximant phases, the amount and morphology of which depend on both the shield composition and crystallization mode. The optimum annealing time for the cast samples at 800°C has been determined, resulting in complete transformation of approximant crystalline phases into a quasi crystalline ico phase.