This study demonstrates that primary care doctors' knowledge of SW is limited, and that these limitations can lead to stigmatisation and suboptimal treatment. The following recommendations are to: draw up a list of doctors who can welcome SWers without being judgmental and make this list available to associations active in the field of SW; co-construct a training course, in partnership with SWers, aimed at GPs (it would include sections on the historical and legal context, the approach to harm reduction and substance abuse, PreP, PEP, and a communication guide); and teach courses on marginalised populations with specific health needs during the initial training of medical students.