AbstractBackgroundThere is currently no comprehensive legislation protecting non-smokers and children from second-hand smoke (SHS) exposure in private cars at the European Union (EU) level. This study aims to assess smokers’ support for smoke-free cars legislation in six EU countries.MethodsData come from the EUREST-PLUS ITC Europe Surveys: Wave 1 (2016, n = 6011) and Wave 2 (2018, n = 6027) conducted in Germany, Greece, Hungary, Poland, Romania and Spain. Support for smoke-free cars carrying pre-school children and non-smokers and voluntary implementation of smoke-free cars were assessed among adult smokers. Generalized estimating equations models were used to assess changes in support between waves.ResultsIn 2018, 96.3% [95% confidence interval (CI) 95.4–97.0%] of the overall sample supported smoke-free legislation for cars carrying pre-school children, representing an increase of 2.4 percentage points in comparison to 2016. Smoke-free legislation for cars transporting non-smokers was supported by 85.2% (95% CI 83.1–87.1%) of smokers’ in 2016 and 90.2% (95% CI 88.6–91.7%) in 2018. Among smokers who owned cars, there was a significant 7.2 percentage points increase in voluntary implementation of smoke-free cars carrying children from 2016 (60.7%, 95% CI 57.2–64.0%) to 2018 (67.9%, 95% CI 65.1–70.5%). All sociodemographic groups of smokers reported support higher than 80% in 2018.ConclusionThe vast majority of smokers in all six EU countries support smoke-free legislation for cars carrying pre-school children and non-smokers. This almost universal support across countries and sociodemographic groups is a clear indicator of a window of opportunity for the introduction of comprehensive legislation to protect non-smokers and children from SHS exposure in cars.