Abstract Background: Lifestyle factors may affect cancer risk. This study aimed to identify whether American Heart Association (AHA) Ideal Cardiovascular Health (ICH) score and its individual variables in youth associate with subsequent cancer incidence. Methods: Study comprised of participants of the Cardiovascular Risk in Young Finns Study free of cancer at analysis baseline in 1986 (n=1873). Baseline age was 12-24 years and the follow-up occurred between 1986-2018. Results: Among 1873 participants (mean age 17.3±4.1 years; 53.4% females at baseline), 72 incident cancer cases occurred during the follow-up (mean follow-up time 31.4±3.4 years). Baseline ICH score was not associated with future cancer risk (HR 0.96, 95% CI 0.78-1.12 per 1-point increment). Of individual ICH score variables, ideal physical activity (PA) was inversely associated with cancer incidence (age- and sex-adjusted HR 0.45 (0.23-0.88) per 1-category change [nonideal/ideal]), and remained significant in multivariable-adjusted model including also BMI, smoking, diet and socioeconomic status. A continuous physical activity index at ages 9-24 years and moderate to vigorous physical activity in youth were also related to decreased cancer incidence (p<0.05). BMI, smoking, diet, total cholesterol, glucose and blood pressure were not related to cancer risk. Of the dietary components, meat consumption was associated with cancer incidence (p=0.023). Conclusions: These findings indicate that higher PA levels in youth associate with a reduced subsequent cancer incidence whereas AHA´s ICH score in youth does not. Impact: This finding supports the efforts in promoting healthy lifestyle and encourages in physical activity during childhood yielding in subsequent healthier life.