Managing diabetes mellitus in patients in the intensive care unit (ICU) requires vigilant monitoring and tailored treatment strategies due to the complexity and critical nature of their medical condition. Close glucose monitoring is essential, often requiring continuous intravenous or frequent point-of-care glucose measurements to maintain tight glycemic control. Insulin therapy is typically the cornerstone, with protocols adjusting doses based on frequent glucose checks to achieve target levels while avoiding hypoglycemia. In ICU settings, stress-induced hyperglycemia is common and may exacerbate pre-existing diabetes. Thus, strategies aim to manage both underlying diabetes and acute stress-related hyperglycemia. Nutrition support is carefully managed to balance glucose control and meet caloric needs, often involving specialized enteral or parenteral nutrition formulations. Furthermore, comorbidities such as infections and cardiovascular issues complicate diabetes management in the ICU, necessitating a multidisciplinary approach involving endocrinologists, intensivists, and specialized nursing teams. Regular reassessment of insulin requirements, adjustment of therapy based on changing clinical conditions, and attention to potential drug interactions are crucial for optimizing outcomes in critically ill patients with diabetes mellitus in the ICU.