OBJECTIVE: This study aimed to explore the readiness for advance care planning (ACP) among older adults in Macau's day service centers and investigate the influencing factors. METHODS: A cross-sectional study was conducted from October to December 2022 using a convenience sampling method. A total of 312 older adults were selected from 13 day service centers for older adults in Macau, China. The Advance Care Planning Acceptance Questionnaire and the Family Adaptation, Partnership, Growth, Affection, Resolve (APGAR) Scale were used to survey the older adults. RESULTS: A total of 306 older adults completed the survey. The score for advance care planning readiness was 65.55 ± 10.69, and 59.5% of participants ( CONCLUSIONS: Older adults in Macau's day service centers were willing to engage in ACP. The importance of family involvement is highlighted in the ACP readiness. Health education and improved family communication are vital for promoting ACP, which ensures individuals receive care when they lack the capacity to make that choice. Additionally, healthcare professionals should enhance communication and education with older adults during the medical care process.