Real-time radiography using synchrotron radiation X-ray was utilized to directly observe and investigate the formation behavior of Fe bearing intermetallic phases in Al–Si–Cu alloys. Solidification sequences of two Al–Si–Cu alloys with different Fe content were examined in a specially designed vacuum furnace and chamber in BL20XU of SPring-8. Detailed solidification sequence and resultant phases forming reactions were confirmed by combined analyses of radiography, thermodynamic calculation and SEM-EDS. The formation behavior of primary, eutectic and peritectic β-Al₅FeSi as well as α-Al₈Fe₂Si and α-Al₁₅(Fe,Mn)₃Si₂ were explained as a function of Fe content. The β-Al₅FeSi was found to form as only small eutectic component in the low Fe containing alloy, while that was crystallized as a primary phase as well as α-Al₈Fe₂Si and α-Al₁₅(Fe,Mn)₃Si₂ in the high Fe containing alloy.