Stroke remains a leading cause of mortality and long-term disability, particularly among individuals with chronic conditions living in rural areas. Self-care behavior plays a pivotal role in stroke prevention, yet limited evidence exists on how physical functioning influences such behaviors in high-risk populations. This study aimed to examine the relationship between functional status and self-care behavior among adults at high risk of stroke in rural. A cross-sectional correlational study was conducted among 100 adults aged 30 years and above who were identified as high risk for stroke using the Thai Cardiovascular Risk Score (≥20%). Participants were recruited from ten health-promoting hospitals using multi-stage random sampling. Functional status and self-care behavior were assessed using validated self-report questionnaires. Data were analyzed using descriptive statistics and Pearson’s correlation. Participants reported moderate levels of both functional status (M = 55.87, SD = 9.34) and self-care behavior (M = 65.42, SD = 6.78). A statistically significant positive correlation was found between functional status and self-care behavior (r = 0.392, p < 0.001), suggesting that higher functional ability is associated with better engagement in stroke-preventive behaviors. Functional status is a key determinant of self-care behavior in individuals at high risk of stroke. Nurses and healthcare professionals should prioritize interventions that enhance physical functioning to promote sustained self-care practices. Future research should investigate causal relationships and develop function-based health promotion strategies.