Abstract Background Adults experiencing homelessness have higher rates of disease and premature morbidity compared to the general population. Tobacco use is a primary contributing factor to these disparities; however, less is known regarding e-cigarette use patterns among adults experiencing homelessness and whether e-cigarettes are used in a manner that is narrowing or widening health disparities. This study aimed to describe the 1) prevalence and trends in e-cigarette use, 2) correlates of e-cigarettes use, and 3) rates of chronic health conditions by product use pattern in a community-based sample of adults experiencing homelessness. Methods Adults experiencing homelessness in Minnesota were surveyed by self-report in 2015 (n = 3672) and 2018 (n = 4181) regarding e-cigarette and combustible cigarette use, potential correlates of e-cigarette use, and self-reported chronic health conditions (i.e., asthma, hypertension, diabetes, and cancer). Results Frequency of use increased from 2015 to 2018 for combustible cigarettes (66.9% vs. 72.3%), e-cigarettes (11.4% vs. 14.5%), and dual combustible/e-cigarette use (10.2% vs. 12.9%). The strongest bivariate correlates of past 30-day e-cigarette use were younger age, non-binary gender identification, non-heterosexual orientation, identification as White/Caucasian, greater frequency of lifetime homelessness, substance use, lack of regular place for medical care, mental health diagnosis, criminal justice involvement, and combustible cigarette smoking. Dual users had significantly higher rates of asthma and cancer than both those using combustible cigarettes and those using neither combustible nor e-cigarettes. Conclusions During a time when cigarette smoking, e-cigarette use, and dual use were decreasing in the general population in Minnesota, rates increased in the homeless population. We observed that the rates of dual use were more than five times greater among homeless adults compared to the general population in 2018. Correlates of e-cigarette use were identified and should be used to identify subpopulations for intervention targeting. Mechanisms of the relationship between dual use and increased risks of health conditions deserve further study.