This study provides a qualitative exploration of the therapeutic mechanisms occurring within three community-based reading and writing for well-being groups, primarily attended by older adults, located in a large city in England. It is increasingly accepted that community-based participatory arts programmes can contribute to health and well-being (Clift, 2012). However, research in this area has tended to focus on the visual and performing arts, with less attention given to literary interventions. Additionally, whilst the concept of bibliotherapy stretches back centuries, writings on this topic have been predominantly anecdotal and the research literature is thin (Detrixhe, 2010). This study aims to develop a deeper understanding of the therapeutic mechanisms occurring within these groups which facilitate well-being, with the objectives of: 1) enhancing practitioners' ability to effectively implement such interventions, and 2) contributing to the development of a strong theoretical base from which such interventions can be meaningfully evaluated. Twelve individual, semi-structured interviews were conducted for this study and analysed using thematic analysis, following the guidelines of Braun & Clarke (2006). Four overarching themes were developed through the analysis, which are expressed through a relational framework. These include: 'Relationship to self', 'Relationship with others', 'Relationship to facilitator' and 'An intermediary object'. It is concluded that, whilst some of the therapeutic processes are similar to those occurring in other community-based participatory arts programmes, additional key processes are related to unique features of the literary arts, as well as the facilitator's group design, training, and way of relating.