AbstractThe objective of this study was to examine the effect modification of age on the relationship between cancer and prevalence of self‐reported stroke. We used cross‐sectional data from the 2015–2016 iteration of the Canadian Community Health Survey. A multivariable logistic regression model was used to assess the association between cancer and self‐reported stroke. Covariates were assessed for effect modification using the maximum likelihood estimation method. We analyzed 86,809 subjects; the prevalence of self‐reported stroke was 1.11%. The odds ratio for the association between cancer and self‐reported stroke was 1.26 (95% CI 0.98–1.61) after adjusting for age, sex, dyslipidemia, hypertension, diabetes, heart disease, education, and household income. Age and hypertension were found to be effect modifiers, and the association between cancer and self‐reported stroke was stronger in younger adults and in those without hypertension. These results suggest that cancer‐associated strokes may have unique underlying mechanisms compared to conventional strokes.