Arrhythmias are the most commonly encountered cardiovascular complications during anesthesia administration. Perioperative arrhythmias disrupt the hemodynamic state of the patients and are known to cause increases in mortality and morbidity. Anesthetic agents and methods affect cardiac conduction and cause arrhythmia. At the same time, patients with additional cardiac diseases and other systemic diseases affecting the cardiovascular system have increased risk of perioperative arrhythmia. For the patient, regardless of whether due to the surgical procedure or anesthesia type, the most important effect of intraoperative arrhythmias is undoubtedly the resulting hemodynamic instability. It is possible to encounter a broad range of serious rhythm and hemodynamic disorders from rare ventricular extrasystole to malignant character arrhythmia and sudden cardiac arrest. Temperature changes occurring in the intraoperative period, hypoxia, acid-base disorders and variations in electrolyte balance are significant factors affecting the occurrence of arrhythmia. As there are many factors and mechanisms in the etiology, identifying arrhythmia under anesthesia and performing the necessary intervention in the shortest time possible has vital importance. This review deals with the importance of arrhythmia occurring in the perioperative period and methods of approach for arrhythmia.