There is limited research into the value, purpose and function of Mental Health (MH) Chaplains. Yet, they are employed within National Health Service Trusts in the UK. Eight MH Chaplains were interviewed to explore how they see their value, purpose and function. The data were analysed using interpretative phenomenological analysis. The data reveal the relational and spiritual/existential accompaniment nature of their work, which is of transformative value, and which requires MH Chaplains to be able to offer "hospitality" and to work at relational depth which is akin to working with the spiritual dimension of clients within counselling. Other roles include: religious care; offering a visible presence; running groups; training; advocacy; connecting with other services; community liaison; committee work; and staff support.