This paper reports a pilot study exploring mental health nurse prescribers' perceptions of barriers to prescribing independently but also includes perceptions of barriers to supplementary prescribing. Current prescribing practice as experienced by mental health nurses suggests a need to identify and highlight these barriers. A mixed methodology explanatory sequential study was carried out over 3 months in Scotland in 2008 as part of a Master's degree. A questionnaire was completed by 33 mental health nurse prescribers. A focus group was conducted with 12 mental health nurse prescribers. Participants' views exposed a number of barriers to prescribing previously unidentified in a review of the relevant literature, and concurred with some previously documented barriers. Sixty per cent of mental health nurse prescribers in the study were not prescribing. Barriers identified in the study included concern about how prescribing impacts on the therapeutic relationship, role conflict, lack of support, inappropriateness of prescriber training, remuneration, qualifying to prescribing time, supervision, prescribing policies, clinical governance and nurse management. Nurse prescribing involves increased accountability and responsibility which is not currently recognized in job status or pay banding. Mental health nurse prescribing has the potential to enhance service provision, but until barriers to prescribing have been identified and addressed as part of the process of organizational change, nurse prescribing cannot achieve its maximum potential.