Background: Type 2 diabetes is a disease which causes vascular damage, stroke and premature death.Oxidative stress may play a role in the development of insulin resistance and diabetes. Selenium is amineral involved in the protection against oxidative stress, and has been thought to be favorable in theprevention of the disease. However, this has changed since trials observed positive correlationsbetween high selenium levels and incidence of type 2 diabetes.Objective: To examine the studies that investigates seleniums effect on the incidence of typ 2 diabetesSearch strategy: Searches have been done in PubMed and Scopus.Selection criteria: Included studies were human studies in English/Swedish with RCT or cohortdesign with the aim to investigate the correlation between selenium and incidence of type 2 diabetes.Excluded studies were studies whose aim was to investigate the role of selenium in patients withexisting diabetes. Studies regarding pregnant women, animals or children and with in vitro design werealso excluded. Of the studies found in Scopus where MeSH terms were available, the ones who did notinclude relevant terms were excluded.Data collection and analysis: Studies were collected according to the aforementioned criteria.