End-of-life sedation remains a controversial and ill-defined clinical practice; its applications vary considerably. With this in mind, a study was conducted using a 2 x 2 experimental design. The variables experimented with were prognosis (short- or long-term) and type of suffering (physical or existential). The goal was to study the influence of the two independent variables on attitude toward sedation. Four clinical vignettes were completed by 124 clinicians, doctors, and pharmacists working in different palliative care environments in the Province of Quebec. The results indicate that the type of suffering influences a subject's attitude to end-of-life sedation. Thus, when a patient was suffering physically, the respondents were significantly in favour of sedation, whereas they were not in favour of this practice if the suffering was existential. Lastly, it is clear that health professionals are uncomfortable when confronted with their patients' existential suffering. This is an issue worth exploring in future studies.