A pre-use check to ensure the correct functioning of anaesthetic equipment is essential to patient safety. The anaesthetist has a primary responsibility to understand the function of the anaesthetic equipment and to check it before use. Anaesthetists must not use equipment unless they have been trained to use it and are competent to do so. A self-inflating bag must be immediately available in any location where anaesthesia may be given. A two-bag test should be performed after the breathing system, vaporisers and ventilator have been checked individually. A record should be kept with the anaesthetic machine that these checks have been done. The 'first user' check after servicing is especially important and must be recorded. Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.