In this study, ferritic and pearlitic ductile irons were joined using a diffusion welding method at different temperatures for different durations. In order to determine the strength of the joints, shear and hardness tests were applied. Additionally, an optical microscopy examination was carried out in order to determine the interface properties of the joint. The work conducted showed that the highest interface strength was obtained for the specimens joined at 1000 degrees C for 60 min. The hardness measurements indicated that the highest hardness value was obtained for the interface and the hardness values on both sides of the interface decreased gradually.