The stretcher comprises a headrest (1a) movable with respect to a body section (1b) between a plurality of possible positions parallel to one another, and positional adjustment means for adjustably regulating the position adopted by the headrest (1a) with respect to the body section (1b). Its use is for keeping the upper airway of a patient laying face-up on the stretcher (1) clear by tilting his/her head back by means of the corresponding movement of the headrest (1a) with respect to the body section (1b). The headrest assembly comprises: a support (S) for fixing it to a body section of a stretcher or bed a headrest (1a) linked to the support (S) in a manner moveable with respect to same between a plurality of possible positions parallel to one another, and positional adjustment means for adjustably regulating the position adopted by the headrest (1a) with respect to the support (S).
