In this study, the strain ageing behaviour of AISI 430 ferritic stainless steel is investigated. A certain part of the as-received ferritic stainless steel test pieces was pre-strained for 5 % in tension, then aged at 100, 200, 300, and 400 degrees C for 30 min in a furnace. The other part was solution heat-treated at 950 degrees C for 15 minutes, water quenched and pre-strained for 2 or 5 % in tension, then aged at 100, 200, 300, and 400 degrees C for 30 min. UTS (ultimate tensile strength), Delta Y (increase in yield strength due to strain ageing), percentage elongation and yield point elongation measurements were employed to investigate the effect of strain ageing on the mechanical properties. The experimental work has revealed that different ageing temperatures significantly affect the mechanical properties of the AISI 430 ferritic stainless steel.