Background: Carers’ end-of-life caregiving greatly benefits society but little is known about the monetary value of this care. Aim: Within an end-of-life cancer setting: (1) to assess the feasibility and content validity of a post-bereavement measure of hours of care; and (2) to obtain a monetary value of this informal care and identify variation in this value among sub-groups. Design and setting: A census based cross-sectional survey of all cancer deaths from a 2-week period in England collected detailed data on caregiving activity (10 caregiving tasks and the time spent on each). We descriptively analyse the information carers provided in ‘other’ tasks to inform content validity. We assigned a monetary value of caregiving via the proxy good method and examined variation in the value via regression analysis. Results: The majority of carers (89.9%) were able to complete the detailed questions about hours and tasks. Only 153 carers reported engaging in ‘other’ tasks. The monetary value of caregiving at end-of-life was £948.86 per week with social and emotional support and symptom management tasks representing the largest proportion of this monetary valuation. Time of recall did not substantially relate to variation in the monetary value, whereas there was a stronger association for the relationship between the carer and recipient, carer gender and recipient daily living restrictions. Conclusion: The monetary valuation we produce for carers’ work is substantial, for example the weekly UK Carers’ Allowance only amounts to 7% of our estimated value of £948.86 per week. Our research provides further information on subgroup variation, and a valid carer time instrument and method to inform economic evaluation and policy.