Ball milling is an effective technique for synthesis of nanocrystalline materials.Cryomilling is a new version of ball milling which benefits from ball milling at cryogenic temperatures.Two different methods have been applied for cryomilling.In most cases,a cryogenic liquid (e.g.liquid N2) flows continuously inside the mill vessel.The raw materials are ball milled with the cryogenic liquid forming a slurry.In some set-ups the cryogenic temperature during ball milling has been achieved by circulation of cryogenic liquid around the outside surfaces of milling vessel.Basically,cryomilling experiments can be carried out in any type of milling apparatus although the attrition ball mill is often preferred.Cryomilling process includes several advantages over room temperature ball milling.