Cilostazol is used to reduce the symptoms of intermittent claudication (pain in the legs that worsens when walking and improves when resting that is caused by narrowing of the blood vessels that supply blood to the legs). Cilostazol is an antiplatelet drug and a vasodilator. It works by stopping blood cells called platelets from sticking together and prevents them from forming harmful clots. It also widens blood vessels in the legs. Cilostazol helps the blood to move more easily and keeps blood flowing smoothly in your body.