AbstractAs one of the fatal complications, venous thromboembolism (VTE) is associated with increased mortality. However, the combined effects of adopting multiple healthy lifestyles have not been firmly demonstrated. This study was to evaluate the association of combined healthy lifestyles and genetic risk factors with VTE and to investigate their interaction. A prospective cohort study from UK Biobank with a total of 442,963 men and women aged between 38 to 73 years were recruited from 2006 to 2010 and followed up through 2017 or 2018. A polygenic risk score was constructed and a weighted healthy lifestyle score, including no current smoking, regular physical exercises, healthy diet, and healthy body mass index, was categorized. During a median follow-up 9.0 years (3,912,396 person-years), there were 6,736 (172 per 100,000 person-years) incident VTE cases recorded. Among the participants with an unfavorable lifestyle, 1.80% developed VTE, versus 1.03% of the participants with a favorable lifestyle (hazard ratio [HR]: 1.58; 95% confidence interval [CI]: 1.48–1.68). Of the participants with high genetic risk, 2.42% developed VTE, versus 0.97% of the participants with low genetic risk (HR: 2.60; 95% CI: 2.39–2.81). Moreover, of the participants with high genetic risk and unfavorable lifestyle, 2.90% developed VTE, versus 0.66% of the participants with low genetic risk and favorable lifestyle (HR: 4.09; 95% CI: 3.48–4.79). No significant interaction between genetic risk and lifestyle factors was observed (p for interaction = 0.727). An unfavorable lifestyle was associated with a substantially higher risk of VTE, regardless of the genetic risk strata.