The management of diabetes during terminal illness is complex, with lack of agreement and consensus among physicians and multidisciplinary teams. Despite the plethora of guidelines available for the management of diabetes, there exists no agreed, evidence-based strategy for managing diabetes during terminal illness and at the end of life. A number of physiological factors may influence glycaemic control during terminal illness. These include anorexia, cachexia, malabsorption, renal and hepatic failure. Furthermore, controversy exists on the frequency of blood glucose monitoring, the optimum blood glucose range and how to achieve this. We review the factors influencing blood glucose during terminal illness and provide a suggested approach to managing patients with type 1 and type 2 diabetes during the early and late stages of terminal illness.