Background Family carers provide substantial support for patients at end-of-life. It is important to understand how caregiving impacts on carers to guide appropriate interventions to improve carer wellbeing. The aims of this study were to investigate levels of psychological distress and predictors of distress during end of life care giving in a national sample of family carers of people with cancer. Methods Four-month post-bereavement postal survey of a national census sample of relatives reporting a death from cancer 1–16th May 2015.