<p>Provided is a leak detection system which can effectively detect a leak even when a patient has moved during administration of a chemical liquid and the movement has caused a leak of the chemical liquid out of a blood vessel. The leak detection system (1) includes: a leak detection device (20) which detects a leak out of a blood vessel during administration of a chemical liquid to a patient; and a transmission means which radio-transmits to a monitor terminal, the information relating to the leak out of the blood vessel detected by the leak detection device (20).</p>
