Tehran University of Medical Sciences Journal of Sleep Sciences 2476-2938 4 3-4 2020 07 01 91 92 Shahram Samadi Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Arezu Najafi Occupational Sleep Research Center, Baharloo Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2020 04 19 2020 06 14 "In its simplest and most positive terms, sleep is a desired state of unconsciousness". Anesthesia in the contrary is another type of “desired unconsciousness”. However, they are actually like the two unequal twins sharing some features but different in others. Sleep and anesthesia are different in several aspects making them unique neu-rophysiologic states with complex mechanisms of action. Here, we aimed to compare these two states concisely, that may be a source of more interesting scientific pearls for whom working in this field especially sleep medicine specialists. https://jss.tums.ac.ir/index.php/jss/article/view/164