Understanding crystallization of amorphous metals is essential for the production of amorphous ribbons and powders and for the production of larger bodies by means of consolidation of an amorphous alloy powder. In this paper, we describe the evolution of the crystalline phases that form upon crystallization of amorphous Al₈₄Y₉Ni₅Co₂ ribbons during heating in a differential scanning calorimeter. X-ray diffraction and transmission electron microscopy (TEM) with energy dispersive spectroscopy were used to determine the phases formed. Crystallization occurs in three stages: (1) primary crystallization of α-Al, (2) formation of an unknown phase, and (3) formation of Al₃Y, Al₉Co₂ and `Al₁₆Ni₃Y' needles.