In recent years, advance care planning (ACP) promotion in Taiwan has expanded beyond clinical practice to the broader population. This study aims to investigate people’s attitudes toward ACP and to identify factors influencing their signing of advance directives (ADs) and appointment of health care agents (HCAs). Methods: We identified 2337 ACP participants from consultation records between 2019 and 2020. The relationships among the participants’ characteristics, AD completion, and HCA appointment were investigated. Results: Of 2337 cases, 94.1% completed ADs and 87.8% were appointed HCAs. Welfare entitlement (OR = 0.47,p< 0.001), the place ACP progressed (OR = 0.08,p< 0.001), the participation of second-degree relatives (OR = 2.50,p< 0.001), and the intention of not being a family burden (OR = 1.65,p= 0.010) were significantly correlated with AD completion. The probability of appointing HCAs was higher in participants with family caregiving experience (OR = 1.42,p< 0.05), who were single (OR = 1.49,p< 0.05), and who expected a good death with dignity (OR = 1.65,p< 0.01). Conclusions: Our research shows that adopting ACP discussion in Taiwan is feasible, which encourages ACP conversation and facilitates AD completion. Implications: Male and younger adults may need extra encouragement to discuss ACP matters with their families. Limitations: due to sampling restrictions, our data were chosen from an urban district to ensure the integrity of the results. Furthermore, interview data could be collected in future research to supplement the quantitative results.