The microstructure of an Al–Mn–Be–Cu alloy was characterised after melt spinning and heat-treatment at different temperatures. The optimised melt-spinning parameters made it possible to obtain ribbons with thicknesses ranging from 30 to 200μm, having a microstructure composed of a supersaturated Al-rich solid solution, finely dispersed icosahedral quasicrystalline (IQC) particles, and a small fraction of Al 2 Cu. The finest dispersion of the IQC-particles, and consequently the highest microhardness, was obtained on the wheel-side. The initial microstructure started to decompose at temperatures around 400°C. The IQC-phase was replaced by the intermetallic compounds τ 1 -Al 29 Mn 6 Cu 4 and Be 4 Al(Mn,Cu). The maximum hardness of the ribbons, which was approximately 50% higher than in the as-cast state, was attained after heat treatment at 400°C, and could be attributed to the fine dispersion of τ 1 -Al 29 Mn 6 Cu 4 and IQC-particles.