Addiction nurses are highly skilled providers of holistic care and ensuring workforce sustainability is key to providing quality care to a traditionally marginalised group of healthcare consumers. The aim of this study was to explore perceived stigma towards the addiction nursing speciality, addiction nursing (also known as alcohol and other drug nursing) and its impact on workforce sustainability, retention and recruitment. Secondary analysis of qualitative interview data with nurses (n = 50) and survey data (n = 337) was conducted as part of a workforce mapping exercise in 2019. COREQ reporting guidelines were used. After structural coding was applied, three themes emerged: stigma experienced by clients of alcohol and other drug treatment services, stigma experienced by addiction nurses and a lack of awareness of the specialty of addiction nursing itself. Participants overwhelmingly felt that these forms of stigma made addiction nursing less attractive to new entrants, particularly new nurses and posed a threat to the sustainability of the specialty. The findings from this study indicate that urgent attention is required to address stigma towards individuals who use alcohol and other drugs, and the nurses providing care for them. Furthermore, creating awareness of the addiction nursing specialty is paramount to ensure workforce sustainability and to improve care for individuals who use alcohol and other drugs. Beyond addiction nurses, our results indicate that stigma towards other specialties (such as mental health nursing) is a substantive barrier to workforce sustainability.