<b><i>Background:</i></b> Assisted dying and continuous deep sedation (CDS) are controversial practices. Little is known about the perceptions of physicians and surrogates about these practices for patients with advanced dementia. <b><i>Objectives:</i></b> To describe and compare physician and surrogate agreement with the use of assisted dying and CDS in advanced dementia. <b><i>Design, Setting, Subjects:</i></b> Physicians (<i>n</i> = 64) and surrogates (<i>n</i> = 168) of persons with advanced dementia were recruited as part of a randomized controlled trial in Switzerland that tested decision support tools in this population. <b><i>Methods:</i></b> At baseline, the participants were asked about their agreement with assisted dying and CDS in advanced dementia using the following response options: “completely agree,” “somewhat agree,” “somewhat disagree,” “completely disagree,” and “do not know.” Multivariable logistic regressions compared the likelihood that surrogates versus physicians would completely or somewhat agree (vs. completely or somewhat disagree) with these practices. <b><i>Results:</i></b> The physicians and surrogates, respectively, had a mean age (SD) of 50.6 years (9.9) and 57.4 years (14.6); 46.9% (<i>n</i> = 30/64) and 68.9% (<i>n</i> = 115/167) were women. A total of 20.3% (<i>n</i> = 13/64) of the physicians and 47.0% (<i>n</i> = 79/168) of the surrogates agreed with assisted dying in advanced dementia. Surrogates were significantly more likely to agree with this practice than physicians (adjusted odds ratio, 3.87; 95% CI: 1.94, 7.69). With regard to CDS, 51.6% (<i>n</i> = 33/64) of the physicians and 41.9% (<i>n</i> = 70/169) of the surrogates agreed with this practice, which did not differ significantly between the groups. <b><i>Conclusions:</i></b> The surrogates were more agreeable to considering assisted dying in the setting of advanced dementia than the physicians, and about half of the participants in both groups reported CDS to be an appropriate option for this population.