The tobacco industry has used recent findings from the Youth Risk Behavior Surveillance System Survey (YRBSS) to claim that a sales restriction on flavoured tobacco products might increase youth combustible cigarette use. In this special communication, we examined YRBSS data and reached the opposite conclusion. We observed the patterns in youth cigarette smoking in Oakland, California following its 2017 convenience store flavoured tobacco sales restriction. We also found that 2019 YRBSS data from San Francisco, California cannot be used to evaluate the effect of the sales restriction on all flavoured tobacco products in San Francisco as the YRBSS data for this city were collected prior to enforcement of the sales restriction. For future studies, we suggest triangulating with corroborating sales, behavioural and qualitative data over time to assess the effects of tobacco control policies on youth tobacco use. We recommend that policy enactment and enforcement dates, as well as the exact data collection periods for population health surveys, be published to facilitate more rigorous policy evaluation.