A dissonance between espoused values of consumerism within mental health care and the ‘reality’ of clinical practice has been firmly established in the literature, not least in terms of service user involvement in care planning. In order to begin to minimize such dissonance, it is vital that mental health nurse perceptions of service user involvement in the core activity of care planning are better understood. The main findings of this qualitative study, which uses semistructured interviews, suggest that mental health nurses value the concept of user involvement but consider it to be problematic in certain circumstances. The study reveals that nurses hold similar views about the ‘meaning’ of patient involvement in care planning but limited resources, individual patient characteristics and limitations in nursing care are the main inhibiting factors. Factors perceived as promoting and increasing user involvement included: provision of accurate information, ‘user-friendly’ documentation, mechanisms for gaining service user feedback, and high staff morale.