IntroductionStudies have shown that electronic cigarettes have gained immense popularity and their use has increased dramatically all over the world. However, little is known about the knowledge and attitudes towards e-cigarettes in third world countries such as Pakistan. The aim of this study was to determine the perceptions of teenagers in Karachi regarding e-cigarettes and whether the differences in said perceptions were affected by gender and level of education.MethodsWe conducted a cross-sectional study in January 2017 using convenience sampling and interviewed 441 young individuals, aged 13 to 19 years, to determine their knowledge, attitudes, and practices regarding e-cigarettes. The participants were questioned about their knowledge and its source. Attitudes were judged using four and five-point Likert scales while questions regarding practices focused on single and current use. Chi-square and Mann-Whitney tests were applied to compare the knowledge, attitudes, and practices of teenagers with gender and level of schooling.ResultsThe majority of participants knew what e-cigarettes were (n=277, 68.7%) but did not know about their contents (n=225, 55.8%) and had learned about them from either friends or the internet (n=245, 60.%). Almost half of them (n=190, 47.2%) believed that the reason for e-cigarette use was either peer pressure or to quit smoking conventional cigarettes. An overwhelming majority also stated that; it was either easy or very easy to obtain e-cigarettes (n=277, 68.7%), they would not try smoking e-cigarettes even if a good friend of theirs recommended them (n=287, 71.2%), they were not current e-cigarette smokers (n=370, 91.8%) and they would never promote e-cigarette use (n=371, 92.1%). Statistically significant differences were found with males knowing more about e-cigarettes (p=0.006) and being more common to either have smoked (p <0.001) or be current e-cigarette smokers (p <0.001). Furthermore, middle school students were more likely to have negative attitudes towards e-cigarettes believing they were more harmful (p=0.003) and more addictive (p <0.001) than conventional cigarettes.ConclusionMany people were aware of what electronic cigarettes are but still, it was evident that there was the lack of proper knowledge along with negative attitudes towards e-cigarette use among teenagers in Pakistan due to cultural and social stigmas and lack of advertising. Males and females had considerable differences in their opinions regarding e-cigarette use owing to such social practices being considered taboo by females and males having greater freedom due to patriarchal, familial and cultural systems.