A support for an oxygen diffuser for delivering a plume of oxygen-enriched air to a space in front of a patient's nose and mouth. The support comprises a means for holding a tube associated with the oxygen diffuser. This means is located at the vertex of front portions of rigid arms forming a v-shaped front of the support. A resilient front strap extends between rear portions of the arms. A resilient back strap extends between ends of the rear portions of the arms. In operation, the back strap is arranged so as to extend behind a user's head and is releasably adjustable to an operative length to seat the support securely on a user's head with a portion of the front of the user's face bearing against the front strap, so that, when so seated, the diffuser is held in a position spaced from but proximal to the patient's nose and mouth.