Amateur theatre has often suffered from a stigma of incompetence, and the view that while participants enjoy their involvement, they are unable to impact on the professional realm. Recent policy from Arts Council England and major projects from the Royal Shakespeare Company and National Theatre Wales suggest the amateur contribution is increasingly being recognised and celebrated. This article explores the emerging role of the non-professional in contemporary British theatre through the 'Pro-Am' initiative-whereby amateurs and professionals work collaboratively. It initially considers how serious leisure theories such as collective amateurism, flow, subjective well-being, social identity and culture of commitment can be applied to the Pro-Am theatre context and explore the challenge of negotiating the commitments of a serious leisure pursuit with participants' 'real lives'. Methods employed include case study, semi-structured interviews, observation and a focus group. Data are presented from the perspective of professional practitioners who facilitate Pro-Am work in regional, producing theatres and other industry experts, supported by some additional participant comments. Implications for arts organisations delivering this kind of work are then addressed. Findings reflect many of the outcomes outlined in the theory, and we conclude that the broadening of categories and the increasing popularity of Pro-Am initiatives are breaking boundaries, changing the very nature of amateurism.