Objectives: In 2017, one in four French 17-year-olds was a daily smoker, even though France prohibited the sale of tobacco to under-18 minors in 2009. This research aims to evaluate the retail violation rate for sale to minors (RVRms) and the associated factors.Study design: The study design used is observational mystery shopping study.Methods: We conducted a mystery shopping study enlisting 12-year-old and 17-year-old youths in a representative sample of 527 tobacco outlets during three weeks in spring 2019. Multinomial Logit and Probit regressions were estimated on the data collected.Results: The law is not respected. Two of three sellers (65.2%) were willing to make an illegal sale to a 17-year-old minor, and almost one in 12 (8.1%) were willing to sell to a 12-year-old child attempting to buy tobacco. Illegal sales were more likely to be made by male sellers, retailing in big cities, when there were no in-shop queues, and to 17-year-old females. The absence of the mandatory enforcement poster flagging up the ban on the sale of tobacco to minors appears to be a strong factor associated with RVRm.Conclusions: These findings show that progress needs to be made to better enforce tobacco control legislation to help decrease underage smoking in France. Rate of compliance with the law could be improved by stronger enforcement measures and tougher sanctions, but also by training and the provision of age-verification tools for sellers, as demonstrated by experiments in other countries.