The issue of rational suicide of a competent patient suffering from a hopeless but not terminal disease is controversial. Little is known about how psychiatrists, other physicians or judges make decisions about involuntary hospitalization of such patients, or about their ethical reasoning. The objective of this study was to identify future physicians' and lawyers' views on involuntary hospitalization of a suicidal Huntington's disease (HD) patient and to evaluate whether they are ethically defendable. Five-hundred and ninety-nine law students and advanced medical students reported whether they agree or not to involuntary hospitalize a suicidal HD patient (audio/video recording). No significant differences were found between medical and law students. Forty-four percent of students agreed to hospitalization, 49.3% disagreed. The comments indicate that medical and law students had pessimistic views about the quality of life of an HD patient. Medical students referred more often than law students to patients' autonomy rights and less often to benefits to relatives. Involuntary hospitalization of a suicidal but not terminal HD patient is controversial among future physicians and lawyers. Students underestimated the need for careful evaluation. More open discussion and more ethical teaching on the subject of acceptance of rational suicide for hopelessly, but not yet terminally ill patients are needed.