Current perspectives on the role of anesthesia in postoperative sleep disorders. Postoperative sleep disorders are attributed to different causes, such as surgical stress, pain, drugs, environmental factors typical of critical patient units and they can cause serious effects that will affect surgical results. Mainly, a decrease in the deep and REM sleep stages is observed in the first two postoperative days with a significant rebound of REM sleep between days two and five, a period in which most of the postoperative complications are also observed. Anesthesia has a minor role in the appearance of sleep disorders, and this depends on the type of anesthesia. General anesthesia induces a desynchronization of the circadian rhythm and is related to a higher incidence of postoperative sleep disorders than regional anesthesia. The magnitude and type of disorders depends on the different types of anesthetics, the mechanism of action on the central nervous system level, the dose used and the time of day in which it is administered, as well as the patient's own conditions such as age or comorbidities. A better understanding of the relationship between anesthesia and the circadian rhythm can have a significant impact on the postoperative recovery of patients.