Diabetes and hyperglycaemia are frequent diagnoses in the hospital, and in-hospital hyperglycaemia is associated with adverse clinical outcomes. Insulin is the preferred treatment for in-hospital hyperglycaemia. This review summarises the management of hyperglycaemia in Danish hospitals. In Denmark, sliding-scale insulin is often applied with the addition of basal insulin after 1-2 days with hyperglycaemia which differs from international guidelines recommending a basal-bolus regimen. The optimal non-intensive care unit glucose targets, the safety and efficacy level of non-insulin antidiabetic agents, and continuous glucose monitoring are subjects of further research.