Background: currently, there is an intensive debate about the regulation of the use of electronic cigarettes (e-cigarettes) in indoor places. The aim of this study was to assess the attitudes toward e-cigarette use in indoor workplaces and selected public and private venues among the general population in Barcelona (Spain) in 2013-2014. Methods: this is a cross-sectional study of a representative sample of the population of Barcelona (n5736). The field work was conducted between May 2013 and February 2014. We computed the prevalence and the adjusted odds ratios(OR) derived from multivariable logistic regression models. Results: the awareness of e-cigarettes was 82.3%. Forty five percent of respondents did not agree with the use of e-cigarettes in public places and 52.3% in workplaces. The proportion of disapproval of the use of e-cigarettes in indoor places was higher at 71.5% for schools and 65.8% for hospitals and health care centers; while the prevalence of disapproval of e-cigarette use in homes and cars was lower (18.0% and 32.5%, respectively). Respondents who disagreed on the use of e-cigarettes in indoor workplaces were more likely to be older (OR51.64 and 1.97 for groups 45-64 and §65 years old, respectively), those with a high educational level (OR51.60), and never and former smokers (OR52.34 and 2.16, respectively). Increased scores in the Fagerstro¨m test for cigarette dependence were also related to increased support for their use. Conclusions: based on this population based study, half of the general population of Barcelona does not support the use of e-cigarettes in indoor workplaces and public places, with the percentage reaching 65% for use in schools, hospitals and health care centers. Consequently, there is good societal support in Spain for the politicians and legislators to promote policies restricting e-cigarettes use in workplaces and public places, including hospitality venues.