Diabetes mellitus (DM) is a chronic metabolic disorder in which prevalence has been increasing steadily all over the world. As a result of this trend, it is fast becoming an epidemic in some countries of the world in the next decade due to increase in ageing population, thereby adding to the already existing burden for healthcare providers, especially in poorly developed countries. Sweet potato (Ipomoea batatas) is a plant found in the tropical and subtropical belts and is one of the most nutritious tropical and subtropical vegetables. As well as being popular in cooking in countries in Asia‐Pacific, Africa and North America, sweet potato is also used in traditional medicine for the treatment of diabetes mellitus. Research in animal and human models suggests a possible role of sweet potato in glycaemic control. This review article evaluated the effects of sweet potato for type 2 diabetes mellitus & also to investigate whether there is enough evidence from medical trials to show whether sweet potato works as a treatment for diabetes. There are many varieties of sweet potatoes and sweet potato preparations. More trials are needed to assess the quality of the various sweet potato preparations as well as to evaluate further the use of different varieties of sweet potato in the diet of diabetic people.