Acute hyperglycemia or stress hyperglycemia commonly occurs in critically ill patients and could be a marker of disease severity. Hyperglycemia at hospital admission is commonly found in patients with cardiovascular disease, regardless of their diabetic status; one of them is arrhythmia. Arrhythmia or dysrhythmia is a heart rhythm disorder that refers to any disturbance in the frequency, regularity, location of origin or electrical impulses conduction of the heart. Arrhythmias associated with stress hyperglycemia include atrial arrhythmias, supraventricular tachycardia (SVT), high-grade (atrioventricular) AV block, and ventricular arrhythmias. Type 2 diabetes was also associated with a significantly increased risk of arrhythmias and sudden death. Hyperglycemia plays an important role in arrhythmia through various mechanisms. In this review, we describe the correlation and mechanism by which arrhythmias may occur in hyperglycemic conditions