Introduction - The exceptional measures taken to curb the spread of the COVID-19 pandemic led to substantial changes in the supply of tobacco products during the first lockdown, from March 17 to May 11, 2020. This paper hypothesizes that changes in purchasing behavior shed light on supply-side phenomena that are more difficult to observe under normal circumstances. These phenomena raise questions about the role of price-hike policies in the absence of tax harmonization at the European level. Methods - Various data from the tobacco dashboards of the French Monitoring Center for Drugs and Drug Addiction (OFDT) were analyzed (sales volumes on a constant-day basis for deliveries made in mainland France through the tobacco retailer network, put into perspective with other indicators such as those related to customs seizures or the nicotine replacement therapy market). Results - In the second quarter of 2020, tobacco sales increased by 5.5% on a constant-day basis across mainland France, with a more pronounced rise in border departments (+21.9% versus +2.4% in non-border departments). This quarterly trend runs counter to the continuous downward trend in sales volumes since 2017. Sales of smoking cessation products also slowed during weeks 12 to 22 of the lockdown (+5.2% compared to the same period in 2019), as did the number of seizures and quantities of contraband tobacco. Discussion - Standard sales data raise various issues regarding interpretation, as they only imperfectly reflect actual consumption patterns, as evidenced by the fact that consumption remained relatively stable during the first lockdown. Tax and price increases, when integrated into a comprehensive anti-tobacco policy, do lead to a decline in sales and smoking prevalence; however, they raise issues regarding tax harmonization and the management of substitution strategies between tobacco products, whether abroad or on the contraband market.