For a variety of reasons, nurses, midwives and health visitors may have to be involved in administration of many types of medical gases. In order to provide safe and effective care the nurse must be aware of the implications of his/her practice. This article discusses and describes the many types of medical gases available in clinical practice. The article focuses on four commonly used gases: oxygen, air, nitrous oxide and entonox. Practical tips are offered and the focus is made on the safe and effective use of the gases. Details regarding the storage and administration of medical gases are outlined. Finally, some of the potential dangers associated with the gases are discussed.