OBJECTIVE: This study aims to investigate how eHealth use and information-seeking behavior affect older adults' acceptance of genetic testing, focusing on their participation in genetic tests and their willingness to adopt lifestyle changes based on test results. The research highlights the mediating roles of the perceived importance of genetic information (PIGI) and cancer worry. METHODS: This cross-sectional study used secondary data from the Health Information National Trends Survey (HINTS 5, Cycle 4), conducted in 2020. The analysis included 1852 adults aged 60 and above. Two mediation models were tested using SPSS 25. Model 1 examined the relationship between eHealth use, perceived importance of genetic information (PIGI), and genetic test behavior. Model 2 analyzed how cancer information-seeking influences willingness to change lifestyle behavior (WCLB) based on genetic test results, with cancer worry as a mediator. RESULTS: Both models showed statistically significant mediation effects ( CONCLUSION: The study highlights the pivotal roles of PIGI and cancer worry in shaping older adults' acceptance of genetic testing, encompassing both performing genetic test behaviors and adopting lifestyle changes based on test results. These findings offer actionable insights for designing targeted health communication strategies and interventions to enhance genetic testing uptake and foster proactive health management among older populations.