Operating theater

An operating theater (also known as an Operating Room (OR), operating suite, operation suite, or Operation Theatre (OT)) is a facility within a hospital where surgical operations are carried out in an aseptic environment.

Historically, the term "operating theater" referred to a non-sterile, tiered theater or amphitheater in which students and other spectators could watch surgeons perform surgery. Contemporary operating rooms are usually devoid of a theater setting, making the term "operating theater" a misnomer in those cases.