Background Stress hyperglycemia is a common metabolic response to critical illness and severe trauma. It has been demonstrated that perioperative stress hyperglycemia is associated with adverse clinical prognosis and an independent risk factor for postoperative complications and mortality by recent literature. Objective The necessity and importance of intervention in stress hyperglycemia were emphasized. Much attention should be paid to issues in dealing with stress hyperglycemia in clinical work. Content Current knowledge of stress hyperglycemia, including the mechanism and related pathophysiologic changes, are elucidated in this review. Trend The treatment of patients with stress hyperglycemia should be individualized and a reasonable blood glucose level should be get to reduce postoperative complications and improve prognosis.