The phase transformation reactions that occur in Al 85Ni 10La 5 alloy during mechanical milling were studied by using fully and partially amorphous ribbons (comprised of fcc-Al, Al 3Ni, Al 11La 3 and amorphous phases) as starting materials. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) study showed that the Al 3Ni phase crystallized, whereas the Al 11La 3 phase amorphized during mechanical milling. The results reported herein indicated that, irrespective of the phase constitution of the starting materials, the microstructure that evolved following mechanical milling was comprised of the same phases; namely: fcc-Al, Al 3Ni and amorphous phases. Differential scanning calorimetry (DSC) analysis revealed that the difference in the structural stability of the Al 3Ni and Al 11La 3 phases are related to the chemical short-range order of the solute atoms in the amorphous phase. The results described in this paper provide an alternative approach to study glass forming ability during mechanical milling.