Despite advertisement by industry about electronic cigarettes (e-cigarettes) as being safer substitute for regular cigarettes scientific data raises serious concerns regarding its effectiveness. AIM: To assess knowledge and perceptions of post graduate medical trainees (PGs) in Pakistan regarding e-cigarettes and their attitude towards its use for themselves and in their patients. Method: Questionnaire was filled by 406 PGs of various specialties from 5 major cities of Pakistan. Data was analyzed using SPSS 22. Correlations were used to assess the relationship between variables. One-way Anova and Independent Sample t-test were applied. P value Results: Among respondents 59% know of e-cigarettes, majorly through acquaintances (55%) and social media (28%). Males were more likely to know about e-cigarettes ( 0.00)) with 1.86 times more chances to use it in future. On evaluating awareness among different cities, Karachi scored lower than Islamabad (p 0.03) and Lahore (p 0.056) and greater than Multan (p 0.003). Pulmonology PGs were found to have significantly higher chances of knowing about e-cigarettes compared to other disciplines. Significant correlation was found between current smokers and higher chances of their knowing about e-cigarettes and increased likelihood of its use compared to others. PGs with friends using e-cigarettes had 3 times more chances to indulge in it in future (p 0.00). Age was found to have positive correlation of 0.185 with attitude towards use ( 0.004). Conclusion: With growing popularity of e-cigarettes steps to provide medical trainees with updated information about these novel devices of nicotine use need to be taken.