BACKGROUND: There is a paucity of research on e-cigarette use among adults with chronic lung disease. Accordingly, little is known about the factors that may contribute to e-cigarette use in this population. The purpose of this study was to evaluate the relationship between chronic lung disease and e-cigarette use and to determine whether binge drinking moderates this relationship. METHODS: Data were derived from the 2018 Behavioral Risk Factor Surveillance System (BRFSS). Logistic regression was used to test the association between chronic lung disease status and e-cigarette use, controlling for demographic variables and chronic health conditions. We conducted moderation analyses to test the hypothesis that the association between chronic lung disease and lifetime e-cigarette use would be modified by binge drinking. RESULTS: The prevalence of lifetime e-cigarette use was higher among adults with chronic lung disease than among those without, and more frequent binge drinking was associated with an increased likelihood of lifetime e-cigarette use independent of chronic lung disease status. Binge drinking moderated the relationship between chronic lung disease and lifetime use of e-cigarettes such that the association between chronic lung disease and e-cigarette use was weaker among those who engaged in more episodes of binge drinking in the past 30 d. Among those without chronic lung disease, binge drinking was associated with an increased likelihood of e-cigarette use. CONCLUSIONS: E-cigarette use appears to be more common among adults with chronic lung disease. Although binge drinking was positively associated with e-cigarette use, more frequent binge drinking weakened the relationship between chronic lung disease and e-cigarette use. Though future studies are needed to determine precisely how binge drinking affects this association, it is possible that individuals with chronic lung disease who binge drink more frequently use e-cigarettes less frequently, despite an increased likelihood of having ever used an e-cigarette. (ClinicalTrials.gov registration NCT04135404.).