Abstract Background Evidence on modifiable risk factors for dementia is accumulating rapidly, including e.g. smoking, hypertension, and diabetes. Comparing knowledge of risk factors for dementia and factors associated with knowledge and motivation to learn about dementia risk reduction in different countries may support the design of tailored public health campaigns. We investigated (1) differences in knowledge of risk and protective factors for dementia between the Netherlands and Germany, and interest in (2) information on brain health and (3) eHealth for brain health. Materials and methods Population-based telephone (Germany) or web-based surveys (Netherlands) were conducted among adults aged 60–75 (n total =614; Germany: n = 270; Netherlands: n = 344), assessing sociodemographic factors, knowledge of risk and protective factors for dementia, interest in information on brain health and respective eHealth-tools. Correlates of knowledge, interest in information on brain health and eHealth for brain health were analyzed using multivariable regression, by country and in pooled analyses. Results In the total sample (M age : 67.3 (SD: 4.3) years; % female : 48.6), knowledge of risk and protective factors (sum score assessing number of correctly identified factors) was higher among German participants (M (SD) = 7.6 (2.5) vs. 6.0 (4.3), p < .001). This was confirmed using linear regression analyses, controlling for sociodemographic covariates (b = 1.51; 95% CI: 1.00; 2.01). High education was linked to better knowledge of risk and protective factors (b = 1.61; 95% CI: 0.89; 2.34). Controlling for covariates, interest in information on brain health (OR: 0.05, 95% CI: 0.02; 0.09) and eHealth for brain health (OR: 0.40, 95% CI: 0.25; 0.65) was lower in German participants. Widowed participants were less interested in information on brain health, while widowed and single participants expressed less interest in eHealth for brain health in pooled analyses. Further associations between sociodemographic factors, interest ...