The study was in two parts. In Part 1 the thematic content analysis of the nurses’ individual accounts of their trial experience revealed how the CMHNs’ aimed to be an agent of change in the nurse-patient encounters and how the trial setting contrasted with everyday practice. Following this, detailed micro-analysis of the narratives of nurse-patient encounters found that the nurses’ goal to be an agent of change was not always borne out when the construction of their accounts was examined. In Part 2 the thematic content analysis of group discussions about CMHN role illuminated the tensions in CMHNs’ everyday practice and their perceived role with people with CMHPs outside of the experimental setting. Overall, the treatment of people with CMHPs was exceptional in that the nurses interpreted their trial experience in the way it contrasted with their everyday practice. Further, in line with the results of the randomised controlled trial, CMHNs did not think that people with CMHPs should be treated by specialist nurses within community mental health services. The nurses suggested a range of methods in which individual, community and primary care resources could be augmented to support people with the aim of preventing referral to specialist services. The integration of the key findings from both parts of the study demonstrated how the nurses used and valued a range of types and sources of knowledge, both in their practice and when forming their views about CMHPs and service organisation. These knowledge sources were not those valued in contemporary healthcare. The dominant evidence-based practice movement champions research evidence of effectiveness above other forms of knowledge. Broadening the understanding of evidence and narrowing the claims of evidence-based practice is suggested to permit all forms of knowledge to be valued in healthcare decision-making