BACKGROUND: Medical decisions concerning the prolongation of life, the right to die and euthanasia are among the most extensively discussed issues within medicine and law today. The purpose of this study was to evaluate the attitudes of medical students and housestaff toward euthanasia. METHODS: From July 15 to September 15 of the 1998, the responses of 180 medical students and 132 housestaff to a self-administered questionnaire were analyzed to identify attitudes toward euthanasia. Over 312 respondents about attitudes toward euthanasia, the analysis of differences between proportions was made by the Chi-square test. RESULTS: About 69.9% of the respondents thought euthanasia should be legalized. The findings suggest that Buddhists (77.5%) and non-religious groups (88.1%) tend to support euthanasia more than Christians. Futhermore, medical students (74.4%) support euthanasia more than housestaffs(63.6%), male(75.1%) more often than female(57.9%). About 73.1% of the respondents said that active euthanasia is not justifiable, and 79.2% said that they do not like performing active euthanasia. In respect to passive euthanasia, 69.0% said that it is not ethically justifiable, but 63.0% would perform this as if it were legal. Housestaffs of internal medicine (76.9%) were more willing to do euthanasia than pediatrics (70.0%), surgery (63.6%), family practice (53.8%) and Ob/Gyn (33.3%). CONCLUSION: Respondents have positive attitudes toward legalization of euthanasia.. Most considered that passive euthanasia is not morally justifiable. But if it were legalized, they would be willing to do euthanasia, while they would still be disturbed by active euthanasia. The opinions of physician and medical students directly affect patient care and their attitudes must be considered if clear policies are to be developed concerning euthanasia.