BACKGROUND AND AIMS: There is conflicting evidence that use of e-cigarettes promotes cessation in regular smokers, but contrasting findings may be due to differing definitions of vaping. The aim was to assess whether regular use of e-cigarettes while smoking is associated with subsequent smoking cessation. DESIGN: Baseline internet survey with outcomes measured at 6-month follow-up. SETTING: All French metropolitan territory. PARTICIPANTS: 2057 smokers aged 15 to 85 years were recruited through an access panel and responded to a 6-month follow-up: 1805 exclusive tobacco smokers and 252 dual users (tobacco plus regular e-cigarette users) at baseline. MEASUREMENTS: The three outcomes assessed at 6 months were: a minimum 50% reduction in the number of cigarettes smoked per day, quit attempts of at least 7 days and smoking cessation of at least 7 days at the time of follow-up. Logistic regressions were performed to model the three outcomes according to regular e-cigarette use at baseline, adjusted for socio-economic variables and smoking behaviours. FINDINGS: Baseline dual users were more likely than baseline exclusive tobacco smokers to have halved cigarette consumption (25.9% versus 11.2%, p <0.001, AOR = 2.6, CI = [1.8-3.8]). Dual users at baseline were also more likely to have made a quit attempt of at least 7 days (22.8% versus 10.9%, p < 0.001, AOR = 1.8, CI = [1.2-2.6]). No significant difference was found for 7-day cessation rates at 6 months (12.5% versus 9.5%, p = 0.18, AOR = 1.2, CI = [0.8-1.9]). CONCLUSIONS: Among people who smoke, those also using an e-cigarette regularly are more likely to try to quit smoking and reduce their cigarette consumption in the next six months. It remains unclear whether regular e-cigarette users are also more likely to stop smoking.[résumé auteur]