Today, e-cigarette use among young adults in the United States, particularly college-age students, is now an emerging, complex and major public health concern. There are a multitude of detrimental health effects associated with e-cigarette aerosol inhalation that could dramatically affect young adults such as: the potential initiation of the regular use of tobacco or other substances, nicotine dependence, adverse effects on brain development, and impaired lung function due to chemicals and flavorings in e-cigarette liquids. E-cigarette use also affects psychosocial health, particularly among youth diagnosed with one or more comorbid mental health disorders and those who are reported to sustain accidental overdose of nicotine. This project aims to estimate the prevalence of lifetime, frequent and current e-cigarette use among college aged individuals during the period of 2016-18 and to assess gender differences on e-cigarette use among college aged individuals. The data to be used for this proposed project is the Population Assessment of Tobacco and Health (PATH) Study. This is a nationally representative longitudinal study of tobacco use and health in the United States. This data will be used to calculate the prevalence of lifetime, frequent, and current e-cigarette use. Initially the selected sample will be categorized based on their socio-demographic and health related characteristics. Overall and gender-specific prevalence estimates will be calculated with their respective standard errors. During analysis, appropriate test statistics (e.g., Chi-square, t-test) will be conducted to assess gender differences in the outcomes of interest. Finally, logistic and negative binomial regression models will be conducted to assess gender differences in lifetime, frequent, and current e-cigarette use while adjusting for potential confounders. PATH analyses weights and linearization procedures will be applied to accomodate for the multi-stage nested cluster sampling design.