Objective: To determine knowledge, awareness, attitude and perception regarding e-cigarette among post graduate medical trainees in Pakistan. Methodology: This cross-sectional online survey was conducted in all over Pakistan during November 2015 to February 2016. A self-administered questionnaire was disseminated through social media groups. Participants were asked to give online consent before filling out the survey. The questionnaire was designed by investigators, which included 26 questions related to participants' demographics, knowledge, attitude and their perception regarding e-cigarettes. Results: A total of 406 complete responses were received. Out of 406, 245 (60.3%) had heard about e-cig. More than half had awareness that e-cigarettes contain nicotine (62%), present in different flavors (75.5%), operated with battery (79.1%), wanted to learn further in future (71.4%), were not comfortable in discussing e-cigarette with their patients (54.7%) and had perception that e-cigarettes were less dangerous than regular cigarette (63.6%). Conclusion: The awareness level regarding e-cigarette in our post-graduate is insufficient and not evidence-based. Majority had incorrect perception that e-cigarette was less dangerous than regular cigarette