Objective: To describe the frequency of support for terminal sedation among internists, determine whether support for terminal sedation is accompanied by support for physician assisted suicide (PAS), and explore characteristics of internists who support terminal sedation but not assisted suicide. Design: A statewide, anonymous postal survey. Setting: Connecticut, USA. Participants: 677 Connecticut members of the American College of Physicians. Measurements: Attitudes toward terminal sedation and assisted suicide; experience providing primary care to terminally ill patients; demographic and religious characteristics. Results: 78% of respondents believed that if a terminally ill patient has intractable pain despite aggressive analgesia, it is ethically appropriate to provide terminal sedation (diminish consciousness to halt the experience of pain). Of those who favoured terminal sedation, 38% also agreed that PAS is ethically appropriate in some circumstances. Along a three point spectrum of aggressiveness in end of life care, the plurality of respondents (47%) were in the middle, agreeing with terminal sedation but not with PAS. Compared with respondents who were less aggressive or more aggressive, physicians in this middle group were more likely to report having more experience providing primary care to terminally ill patients (p = 0.02) and attending religious services more frequently (p,0.001). Conclusions: Support for terminal sedation was widespread in this population of physicians, and most who agreed with terminal sedation did not support PAS. Most internists who support aggressive palliation appear likely to draw an ethical line between terminal sedation and assisted suicide.