PURPOSE: This paper aims to explore smokefree prison policy, from the perspective of people in custody in Scotland. DESIGN/METHODOLOGY/APPROACH: In total, 77 people in custody in Scotland were interviewed in the period leading up to implementation of a nationwide prison smokefree policy. Data were thematically analysed to identify the diversity of views and experiences. FINDINGS: Participants described a widespread awareness in prisons of plans to implement a smokefree policy from 30 November 2018. Opinions about smokefree prisons varied among participants based on perceptions of the fairness, and anticipated positive and negative consequences of removing tobacco from prisons. At the time of the interviews, people in custody were responding to the impending smokefree policy, either by proactively preparing for the smokefree rule change or by deploying avoidance strategies. Participants described opportunities and challenges for implementing smokefree policy in prisons across three main themes: the role of smoking in prison, prison smoking cessation services and motivations for quitting smoking among people in custody. ORIGINALITY/VALUE: This study exploring smokefree prisons from the perspectives of people in custody has several novel features which extend the evidence base. The findings highlight measures for jurisdictions to consider when planning to prohibit smoking in their prisons in the future. These include the need for evidence-based smoking cessation support in advance of smokefree policy, effective communication campaigns, consideration of broader structural determinants of health in prison and ongoing measures to reduce rates of return to smoking post release.