Hyperglycemia is regarded as one of the most important poor prognostic factors that adversely affects the treatment response in patients admitted with medical or surgical condition. The most effective way to treat this serious co-morbidity is by insulin. There are various confusing protocols for the management of in-hospital hyperglycemia in both critical and non critical patients. This article highlights the importance of in-hospital hyperglycemia and simplifies the approach to the treatment of hyperglycemia in various situations.