An oxygen tank key includes an elongated substantially thin flat handle portion defining a first plane and having first and second ends that define the length thereof and first and second side edges that define the width. A socket, integrally formed with the handle portion between the two ends, has a thickness that is greater than the thickness of the handle portion. The socket includes an aperture that opens adjacent one of the side edges and has a depth extending substantially the width of the handle portion. The aperture has a substantially rectangular cross-section and is adapted to fit onto the rectangularly shaped end of an oxygen tank valve control stem. A slot passes through the handle and is elongated in the direction of the length of the handle. The slot includes champhered ends and is adapted to fit over the lever of a regulator for the oxygen tank to help release the regulator from the tank.