Background According to some medical ethicists and professional guidelines, there is no ethical difference between withholding and withdrawing life-sustaining treatment. However, medical professionals do not always agree with this notion. Patients and their families may also not regard these decisions as equivalent. Perspectives on life-sustaining treatment potentially differ between cultures and countries. This study compares Japanese physicians’ and citizens’ attitudes toward hypothetical cases of withholding and withdrawing life-sustaining treatment.Methods Ten vignette cases were developed. A web-based questionnaire was administered to 457 (...) citizens and 284 physicians to determine whether they supported withholding or withdrawing treatment.Results In a case where a patient had an advance directive refusing ventilation, 77% of the physicians and 68% of the citizens chose to withhold treatment. In a case where there was an advance directive but the patient’s family requested treatment, 55% of the physicians and 45% of the citizens chose to withhold the ventilator. When a family requested withdrawal of the ventilator but patient wishes were unknown, 19% of the physicians and 48% of the citizens chose to withdraw the ventilator. However, when the patient had also indicated their wishes in writing, 49% of the physicians and 66% of the citizens chose to withdraw treatment. More physicians were prepared to withdraw dialysis (84%) and artificial nutrition (81%) at a patient’s request than mechanical ventilation (49%).Conclusions A significant proportion of Japanese physicians and citizens were reluctant to withhold or withdraw life-sustaining treatment, even in cases where the patient had indicated their wishes in writing. They were more likely to withhold than withdraw treatment, and more likely to withdraw artificial nutrition than mechanical ventilation. Japanese physicians gave significant weight to family views about treatment but were less likely to agree to withdraw treatment than citizens, indicating a potential source of conflict in clinical settings. (shrink)