The mental health specialist role was introduced by St Vincent’s Hospital Library Service in November 2012. It aimed to raise awareness and uptake of the library’s specialist research services and to improve interdisciplinary and interdepartmental collaboration. Statistics on library services used by mental health staff were collected and compared for 12 months before and after the role was introduced. 80 mental health staff also completed a survey. Statistics showed large increases in mental health staff taking part in educational activities (from 9 to 119 participants), extended research consultations (2 to 54), database tutorials (7 to 28), Endnote tutorials (0 to 13), library orientations (0 to 24), literature search requests (27 to 79) and inter library loans (59 to 250). Psychiatry journal usage increased 91%. As a result of the role 45% of survey respondents improved patient care, 33% modified current practice, 49% considered new viewpoints, 60% saved time, 41% increased productivity, 74% increased current awareness, 76% became aware of what else was happening in their team, 73% used other library resources, 99% read Mental Health Update and 84% read feature articles. 48 additional comments supported the value of the role. Results far surpassed expectations, demonstrating that the specialist role had a significant impact on research and collaboration with mental health staff. The specialist librarian model is effective and could be replicated in other areas.