Aim: Investigate knowledge, attitudes and use of e-cigarettes among Croatian population with validated online questionnaire. Methods: Study included 531 subjects who volunteered to participate and was done using online anonymous questionnaire in 2017; the link to questionnaire was on social media on the University of Applied Sciences Official web site. To limit duplicate responses, one response per IP address was permitted. Specially designed questionnaire using internationally validated surveys: „The young people in Scotland schools omnibus 2014: questions on e-cigarettes“, “Monitoring the future-National survey results on drug results” and The European commission-Special Eurobarometer Report-Attitudes of Europeans towards tobacco and electronic cigarettes. Results: There were 379 (71.4%) women and 152 (28.6%) men in the study. Almost all (97.9%) participants have heard of e-cigarettes. The prevalence rate of the current use of e-cigarettes is (5.8%) of all respondents-9.2% men and 4.5% women. Men know more about e-cigarettes (χ²=8.573, ss=2, p=0.014), and use it more often than women (χ²=4.406, ss=1, p=0.036). The largest number of users are in the age group of 18-30 years, and the largest number of respondents who are seeing advertisements for e-cigarettes see them in social media. People with lower education have tried e-cigarettes more than people with higher level of education (χ²=9.750, ss=3, p=0.020). Cigarettes smokers have more knowledge about composition of e-cigarettes (χ²=7.966, ss=2, p=0.019) and more of them tried e-cigarettes than non-smokers (χ²=5.576, ss=1, p=0.018). Conclusion: Questions related to knowledge show a lack of knowledge of the general population about possible consequences of long-term use e-cigarettes that can be expected. Populations at risk of consuming are younger men, having residency in the city, high school graduates, smokers and former smokers, so public health programs should be created and implemented to that population in cooperation with the educational and health sector.