In the present study, Al-25Zn-3Cu alloy was prepared by permanent mould casting. Fatigue behaviour of the alloy was investigated using a rotating bending fatigue test machine after determining its microstructural features and mechanical properties. It was observed that as-cast microstructure of the Al-25Zn-3Cu alloy consisted of aluminium rich alpha dendrites, eutectoid alpha + eta phases and theta particles. Homogenisation and T6 heat treatment removed the dendritic microstructure of the alloy and produced a large grained microstructure together with zinc rich precipitates. Both heat treatments increased the hardness and strengths of the alloy, but reduced its ductility. The Al-25Zn-3Cu alloy exhibited the lowest and the highest fatigue strengths in the as-cast and T6 heat treated conditions respectively. The fatigue strength of the Al-25Zn-3Cu alloy was found to be much greater than that of the Al-12Si alloy. It was observed that the fatigue behaviour of Al-25Zn-3Cu alloy can be expressed by the Basquin equation.