In the present work, the microstructure of a melt-spun Al-5 Sb alloy has been characterized using X-ray diffraction and transmission electron microscopy. The phases present in the melt-spun Al-5 Sb alloy were determined to be the equilibrium α-Al and AlSb, identical to those in the ingot-cast alloy. The microstructure of the melt-spun Al-5 Sb alloy is composed of primary AlSb phase embedded in the matrix comprising α-Al cells with intercellular nanoscale AlSb particles, different from that of the ingot-cast alloy composed of the primary AlSb phase within an α-Al/AlSb eutectic matrix. Rapid solidification has a marked effect on the morphology, size and distribution of the primary AlSb phase in the melt-spun Al-5 Sb alloy. Furthermore, some orientation relationships were determined in the melt-spun alloy.