X-ray diffraction (XRD) and differential scanning calorimetry were used toinvestigate the crystallization process of amorphous Al90TMxCe10−x alloys.Ageing effects were also examined by means of XRD. The structure correspondingto the prepeak for amorphous Al90Fe5Ce5 alloys is more stable than theamorphous matrix. However, amorphous Al90Ni5Ce5 alloys are not stable duringthe first crystallization stage, and even decompose at room temperature.The crystallization onset temperature for amorphous Al–Fe–Ce alloys ismuch higher than that for amorphous Al–Ni–Ce alloys. This is probablycaused by the different stability of the structure corresponding to theprepeak. The crystallization onset temperature increases as the Ce/Ni ratioincreases in amorphous Al90NixCe10−x alloys. However, the crystallizationonset temperature decreases as the Ce/Fe ratio increases in amorphousAl90FexCe10−x alloys. A better atomic packing results as the Ce contentincreases due to size mismatch in Al–Ni–Ce systems and as the Fe contentincreases due to the increasing size of structural units in Al–Fe–Ce systems.