There is increasing concern that mental health nurses in UK are inadequately trained in medicines management. Recommended solutions entail proposals for further training to improve safety for service users. Although fundamentally important, these organizational approaches lack a conceptual framework to explain how individual practitioners develop competence in medicines management. This is important because applying knowledge of how individuals learn makes strategic interventions more effective. This article presents empirical evidence of how individual mental health nurse prescribers develop competence in prescribing within the context of the therapeutic relationship. It is proposed that these findings can then be extended to inform medicines management training relevant to all mental health nurses, whether prescribers or not. (C) 2010 Elsevier Inc. All rights reserved.