This review mainly focuses on the management of type 2 diabetes in the preoperative setting with a special emphasis on intraoperative glycemic control. Some patients learn their diagnosis of diabetes just prior to the surgery. The prevalence of previously undiagnosed diabetes is reported to be 5,2-10% in literature. Treatment protocols must be tailored individually but evidence based approach in insulin administration and close monitoring of blood glucose are important in order to avoid both hyper and hypoglycemia.