Background and Aims The prevalence of religious faith among doctors and its relationship with decision-making in end-of-life care is not well documented. The impact of ethnic differences on this is also poorly understood. This study compares ethnicity and religious faith in the medical and general UK populations, and reports on their associations with ethically controversial decisions taken when providing care to dying patients. Method A postal survey of 3733 UK medical practitioners, of whom 2923 reported on the care of their (...) last patient who died. Findings Specialists in care of the elderly were somewhat more likely to be Hindu or Muslim than other doctors; palliative care specialists were somewhat more likely to be Christian, religious and ‘white’ than others. Ethnicity was largely unrelated to rates of reporting ethically controversial decisions. Independently of speciality, doctors who described themselves as non-religious were more likely than others to report having given continuous deep sedation until death, having taken decisions they expected or partly intended to end life, and to have discussed these decisions with patients judged to have the capacity to participate in discussions. Speciality was independently related to wide variations in the reporting of decisions taken with some intent to end life, with doctors in ‘other hospital’ specialities being almost 10 times as likely to report this when compared with palliative medicine specialists, regardless of religious faith. Conclusions Greater acknowledgement of the relationship of doctors' values with clinical decision-making is advocated. (shrink)