The effect of pre-deformation on the precipitation process and magnetic properties of Fe-Cu model alloys was investigated. These specimens simulate irradiation embrittlement of nuclear reactor pressure vessel (RPV) steels. Fe-1 wt%Cu alloys with and without pre-deformation in solid-state solution were thermally aged at 773 K for various times and the evolution of hardness, conductivity, and microstructure were investigated. Pre-deformation enhanced Cu precipitation and caused precipitation at dislocations. The coercive force tended to decrease for the pre-deformed specimen and the underlying mechanism is discussed. The results obtained are related to the magnetic characteristics of irradiated RPV steels.