Background During the first wave of the COVID-19 pandemic, a reduction in the number of newly diagnosed cases of lung cancer has been reported worldwide, often associated with a higher proportion of cases diagnosed at an advanced stage compared with previous years. Methods Using the French National Hospital Database, we investigated incident lung cancer cases and their mortality during pandemic years 2020 and 2021, compared to predictions based on pre-pandemic years 2013–2019. Mortality was assessed up to 24 months following incidence date. Expected numbers of incident cases and all-cause deaths during the pandemic were estimated using Poisson regression models and survival was analyzed using Cox regressions. Results The database included 397,092 incident lung cancer cases in total, 20 % of whom underwent thoracic surgery. During the first pandemic wave (March–June 2020), there were 12 % i.e., 1940 fewer incident lung cancer cases than the expected figure (16,325), while no significant difference was found thereafter. Survival at 6 and 24 months improved steadily from 2013 to 2019 and continued to improve during pandemic years 2020–2021. However, during the first wave, a slight excess mortality was observed compared with predictions based on pre-pandemic trends. Conclusions The lower incidence observed during the first wave with no catch-up in the following periods could be explained by deaths among yet undiagnosed patients, either from COVID-19 or as a result of barriers to accessing healthcare. The excess mortality observed for both operated and non-operated patients may be attributable to delayed diagnosis, as well as to COVID-19-related deaths.