Objectives: Treatment decisions in ethically complex situations are known to depend on a physician's personal characteristics and medical experience. We sought to study variability in decisions to withdraw or withhold specific life-supporting treatments in terminal care and to evaluate the association between decisions and such background factors.Design: Readiness to withdraw or withhold treatment options was studied using a terminal cancer patient scenario with alternatives. Physicians were asked about their attitudes, life values, experience, and training; sociodemographic data were also collected.Setting: Finnish physicians, postal survey.Survey sample: Five hundred general practitioners, 300 surgeons, 300 internists, and 82 oncologists.Results: Treatments most often forgone were blood transfusion (82%) and thrombosis prophylaxis (81%). Least willingly abandoned were intravenous (IV) hydration (29%) and supplementary oxygen (13%). Female doctors were less likely to discontinue thrombosis prophylaxis (p=0.022) and supplementary oxygen (p<0.001), but more readilyxray (p=0.039) and laboratory (p=0.057) examinations. Young doctors were more likely to continue antibiotics (p=0.025), thrombosis prophylaxis (p=0.006), supplementary oxygen (p=0.004) and laboratory tests (p=0.041). Oncologists comprised the specialty most ready to forgo all studied treatments except antibiotics and blood transfusion. The family's wishes (alternative 1) significantly increased treatment activity. Young and female practitioners and oncologists were most influenced by family appeal. Advance directives (alternative 2) made decisions significantly more reserved and uniform. Different factors in the physician's background were found to predict decisions to withdraw antibiotics or IV hydration.Conclusion: The considerable variation observed in doctors' decisions to forgo specific life-sustaining treatments (LST) was seen to depend on their personal background factors. Experience, supervision, and postgraduate education seemed to be associated with more reserved treatment decisions. To increase the objectivity of end of life decisions, training, and research are of prime significance in this ethically complex area of medicine.