In this study, using materials thermo-physical data and CAD/CAE techniques the thermal fatigue life of a permanent mould is estimated. 3D solid models of the mould-casting system consisted of a permanent mould made from grade 60 ductile iron and an aluminium 7% Si, 0.3 % Mg Casting alloy (A356) were constructed in a CAD system. After defining all boundary and initials conditions in a finite element environment a thermal solution of the permanent mould casting is achieved repeatedly for every cycle until the steady-state temperature change is reached. The elastic-plastic stress calculation is performed by using the thermal history obtained from the thermal analysis. At the end, the residual stresses are determined and used for the thermal fatigue life estimation. The results showed that using the proposed CAD/CAE techniques the fatigue life of a permanent mould can be estimated.