To identify reasons that college students use JUUL and explore associations between reasons for using JUUL and social and behavioral (tobacco use) factors. On-line, cross-sectional survey. Large southwestern university in the US. Undergraduate students (n = 605) who owned JUUL and used it weekly. The study measured age of JUUL initiation, JUUL dependence, and use of other e-cigarettes and other tobacco products. Participants described reasons for JUUL use as brief open-ended responses. Responses were categorized by 2 researchers using an inductive procedure. Logistic regressions examined associations between demographics and use frequency and categorized reasons for using JUUL. Four reasons for using JUUL emerged: self-help (48.4%), social (30.4%), experience (42.8%), and substance use/addiction (42.3%). Daily JUUL users were 1.66 (95% CI: 1.05-2.63) times as likely to use JUUL for self-help than those who used JUUL 1-3 days/week. Those who had never tried a cigarette were twice (OR = 2.08; 95% CI: 1.22-3.54) as likely as cigarette-first users to use JUUL for social reasons. Males (OR = 1.87; 95% CI: 1.32-2.65) had higher odds of using JUUL for the experience than females, and JUUL and other e-cigarettes users were 4.37 (95% CI: 1.83-10.45) times as likely as JUUL-only users to use JUUL due to substance use/addiction. JUUL users report unique reasons for use (e.g., addiction) not previously reported for older models of e-cigarette devices.