In the context of a growing population of people experiencing mental illness worldwide, mental health nurses are a crucial workforce. Their recruitment and retention, however, is in decline. Drawing on qualitative data obtained from interviews with mental health nurses (MHN) in Victoria, Australia, the paper employs a range of concepts from role theory to explore professional identity within mental health nursing. The data highlight three key issues in relation to the future recruitment and retention of MHN: (i) the ambiguity of the MHN role; (ii) the weak definition and lack of understanding of the scope of the MHN role by nursing students; and (iii) a lack of communication about MHN as a profession to a wider audience. These findings indicate three avenues through which recruitment and retention in mental health nursing could be improved: (i) public communication; (ii) training and educating of the next generation of MHN; and (iii) more accurately defining the role of the MHN.