The improvement of mental healthcare services requires patients' experiences to identify problems and possible deficits in care. In this study, we explored the nature and meaning of formal patient complaints about mental healthcare services in one region of Sweden using a descriptive design with a qualitative approach. A systematic random sample of 106 formal patient complaints about mental healthcare services in 1 Swedish county was selected and analysed thematically, based on descriptive phenomenology. Themes identified were: lack of access to mental healthcare services and specialist treatment, problems related to unmet needs and difficulties with healthcare staff, insufficient care and treatment and lack of continuity in care, and experiences of not been taken seriously or feeling abused by staff. The vulnerability of patients already in the system is a greater issue than realized. The human right to health and the healthcare of patients with mental ill health can be strengthened by increased access to care, listening to patients properly, and delivering continuity in care.