To conduct a systematic review of the use of the recovery position in adults and children with non-traumatic decreased levels of responsiveness changes outcomes in comparison with other positioning strategies. We searched Medline (Ovid), Embase, Cochrane Library, CINAHL, medRxiv and Google Scholar from inception to 15 March 2021 for studies involving adults and children in an out-of-hospital, first aid setting who had reduced levels of responsiveness of non-traumatic aetiology but did not require resuscitative interventions. We used the ROBINS-I tool to assess risk of bias and GRADE methodology to determine the certainty of evidence. Of 17,947 citations retrieved, three prospective observational studies and four case series were included. The prone and semi-recumbent positions were associated with a decreased rate of suspected aspiration pneumonia in acute poisoning. Use of the recovery position in paediatric patients with decreased levels of responsiveness was associated with a deceased admission rate and the prone position was the position most commonly associated with sudden unexpected death in epilepsy. High risk of bias, imprecision and indirectness of evidence limited our ability to perform pooled analyses. We identified a limited number of observational studies and case series comparing outcomes following use of the recovery position with outcomes when other patient positions were used. There was limited evidence to support or revise existing first aid guidance; however, greater emphasis on the initial assessment of responsiveness and need for CPR, as well as the detection and management of patient deterioration of a person identified with decreased responsiveness, is recommended.