Unmet needs in mental health care are a prominent issue and concern almost half of people with such disorders. Psymobile is a mobile outreach psychiatric team whose objective is to facilitate access to psychiatric services. Its intervention is at the request of relatives or social workers, making it possible to encounter situations of long‐standing unmet needs. Our objective was to understand the barriers to accessing mental health care as perceived by patients and their relatives. We conducted a qualitative study with patients and their relatives using face‐to‐face semi‐structured interviews and a hierarchical thematic analysis. Four major themes were identified: psychological and behavioural barriers, socio‐economic barriers, structural barriers and physical barriers. Anosognosia or lack of insight is cited as a primary barrier, as are fear of stigma, and former negative experiences. The complexity of the French care system and the lack of literacy about mental illnesses were also emphasized by the participants. Physical determinants, such as the distance to healthcare facilities, were rarely mentioned. As a conclusion, outreach teams appear to be an appropriate way to address the issue of unmet mental health care needs when they provide psychiatric care.