Undertaking a caregiving role at end of life can have enduring psychological consequences for carers, including poor adjustment in bereavement. Acceptance and commitment therapy–based interventions have demonstrated effectiveness in helping people cope with a range of life challenges. This article presents the protocol of a feasibility randomised controlled trial of an acceptance and commitment therapy self-help intervention for psychological distress and grief in carers of patients in palliative care. We will assess feasibility and acceptability of the trial procedures and intervention as well as preliminary effectiveness of the intervention on carer well-being outcomes.