Subjective perception of air pollution is important and can have impacts on health in its own rights, can lead to protective behaviour, or it can be leveraged to engage citizens and stakeholders in support of cleaner air policies. The aim of the current analysis was to examine associations between level of concern over health effects of air pollution and personal and environmental factors. In seven European cities, 7622 adult participants were recruited to complete an online questionnaire on travel and physical activity behaviour, perceptions and attitudes on active mobility and the environment, and sociodemographics. Air pollution at the home address was determined using Europe-wide PM2.5and NO2land use regression models. Mixed effects logistic regression was used to model concern over air pollution (worried versus not worried; city as random effect). Fifty-eight percent of participants were worried over health effects of air pollution with large differences across cities (Antwerp 78%, Barcelona 81%, London 64%, Orebro 11%, Rome 72%, Vienna 43%, Zurich 33%). Linking mean modelled air pollution to mean level of concern per city gave a good correlation for NO2(r2= 0.75), and a lower correlation for PM2.5(r2= 0.49). In the regression model, sex, having children in the household, levels of physical activity, and NO2at the home address were significantly linked to individual concern over health effects of air pollution. We found that NO2but not PM2.5at the home address was associated with concern over health effects of air pollution.