IMPORTANCE: Little data exist on end-of-life care practices in intensive care units (ICUs) in Asia. OBJECTIVE: To describe physicians' attitudes toward withholding and withdrawal of life-sustaining treatments in end-of-life care and to evaluate factors associated with observed attitudes. DESIGN, SETTING, AND PARTICIPANTS: Self-administered structured and scenario-based survey conducted among 1465 physicians (response rate, 59.6%) who manage patients in ICUs (May-December 2012) at 466 ICUs (response rate, 59.4%) in 16 Asian countries and regions. RESULTS: For patients with no real chance of recovering a meaningful life, 1029 respondents (70.2%) reported almost always or often withholding whereas 303 (20.7%) reported almost always or often withdrawing life-sustaining treatments; 1092 respondents (74.5%) deemed withholding and withdrawal ethically different. The majority of respondents reported that vasopressors, hemodialysis, and antibiotics could usually be withheld or withdrawn in end-of-life care, but not enteral feeding, intravenous fluids, and oral suctioning. For severe hypoxic-ischemic encephalopathy after cardiac arrest, 1201 respondents (82.0% [range between countries, 48.4%-100%]) would implement do-not-resuscitate orders, but 788 (53.8% [range, 6.1%-87.2%]) would maintain mechanical ventilation and start antibiotics and vasopressors if indicated. On multivariable analysis, refusal to implement do-not-resuscitate orders was more likely with physicians who did not value families' or surrogates' requests (adjusted odds ratio [AOR], 1.67 [95% CI, 1.16-2.40]; P =.006), who were uncomfortable discussing end-of-life care (AOR, 2.38 [95% CI, 1.62-3.51]; P <.001), who perceived greater legal risk (AOR, 1.92 [95% CI, 1.26-2.94]; P =.002), and in low- to middle-income economies (AOR, 2.73 [95% CI, 1.56-4.76]; P <.001). Nonimplementation was less likely with physicians of Protestant (AOR, 0.36 [95% CI, 0.16-0.80]; P =.01) and Catholic (AOR, 0.22 [95% CI, 0.09-0.58]; P =.002) faiths, and when out-of-pocket health care expenditure increased (AOR, 0.98 per percentage of total health care expenditure [95% CI, 0.97-0.99]; P =.02). CONCLUSIONS AND RELEVANCE: Whereas physicians in ICUs in Asia reported that they often withheld but seldom withdrew life-sustaining treatments at the end of life, attitudes and practice varied widely across countries and regions. Multiple factors related to country or region, including economic, cultural, religious, and legal differences, as well as personal attitudes, were associated with these variations. Initiatives to improve end-of-life care in Asia must begin with a thorough understanding of these factors.