OBJECTIVE: The awareness and use of e-cigarettes have been increasing in recent years. The World Health Organization recently reported that regulations are needed to impede the promotion of e-cigarettes to young people, prohibit unproven health claims about them (including those regarding smoking-cessation efficacy), minimize potential health risks to e-cigarette users and non-users, and protect existing tobacco controls. The study described herein explored e-cigarette knowledge, perceptions, and usage motivations among a group of adults in Puerto Rico. METHODS: This research study used a validated questionnaire with closed-ended questions to gather data. Non-inferential and inferential statistics were used to characterize smokers (of e-cigarettes, of conventional cigarettes, and of both) and non-smokers. RESULTS: A total of 415 respondents took part; they were evenly distributed by gender, age, and socioeconomic status; all were residents of Puerto Rico at the time of the survey. The overall awareness of e-cigarettes was high, but knowledge of nicotine content and regulations was limited. Asked whether e-cigarettes contain nicotine (they do not), approximately two thirds stated either that they do or that they didn't know; asked whether e-cigarettes are regulated as a tobacco product (they are in Puerto Rico), 84% stated either that they are not or that they didn't know. Common perceptions of e-cigarettes are that they are harmful to health and that they are no less harmful than cigarettes are. However, a significant portion of the respondents perceived e-cigarettes to be less addictive than conventional cigarettes are. Overall, the respondents were divided on the efficacy of e-cigarettes for smoking cessation. Nonetheless, the most common motivation for their use, according to both current users and potential future users, is to aid in smoking cessation or reduction. CONCLUSION: The majority of individuals surveyed were aware of e-cigarettes but had limited knowledge of their contents or regulation. As an aid in smoking cessation was the most commonly mentioned motivation for e-cigarette use.