Abstract Background Despite public support for assisted suicide (AS) and advance directives (AD), no studies have established whether individuals express interest in both procedures. This study investigates the relationship between AD completion and attitudes toward assisted suicide, examining whether Swiss older adults inclined toward AD also demonstrate positive attitudes toward AS. Method Data from 1,523 participants aged 58 and older were collected through the Swiss component of the representative Survey on Health, Ageing, and Retirement in Europe (SHARE) for 2019/2020. Participants were asked if they had completed AD. Attitudes toward AS were assessed using three key questions: support for AS, consideration of it, and membership in a right-to-die organization. Probit regression models analyzed the associations, considering various social, health, and regional characteristics. Results Overall, 42% of the sample had completed AD. Additionally, 81% supported legal access to AS, 63% considered asking for it, and 9% were members of a right-to-die association. Among members of a right-to-die a, 89% had completed an AD. Respondents who had completed AD were more likely to support AS (p < 0.001), consider it (p < 0.001), and be members of a right-to-die organization (p < 0.001). Conclusions The study reveals an association between completing AD and supporting attitudes toward AS among older adults in Switzerland, highlighting how the desire to control end-of-life experiences can drive interest in both procedures. Future developments in end-of-life care planning should consider incorporating discussions and documentation of AD and AS together.