The ductility of irradiated structural alloys is of concern in reactor design. The purpose of this study is to determine some of the parameters affecting such ductility. Type-304 stainless steel has been thus investigated up to 600°C. In general, the ductility of stainless steel, solution annealed prior to irradiation, is better than steel cold worked prior to irradiation. One exception to this generality occurs under the conditions of irradiation followed by straining at 200°C, where low ductility is observed for irradiated stainless steel, solution annealed prior to irradiation. Cold working followed by carbide precipitation at an intermediate temperature improves the ductility of irradiated stainless steel at 200°C.