Technology has significantly changed the way health organizations operate. However, the role it plays in healthcare systems remains unclear. This aim of this study was to evaluate the opinion of physicians regarding e-health and determine what factors influence their opinion and describe the advantages, inconveniences and threats they may perceive by its use. A cross-sectional questionnaire-based study. A questionnaire which had been previously designed and validated by the authors was used to interview physicians from the Barcelona Medical Association. 930 physicians were contacted by phone to participate in the study. Seven hundred sixty physicians responded to the questionnaire (response rate: 82%). The usefulness of telemedicine scored 7.4 (SD 1.8) on a scale from 1-10 (from the lowest to the highest) and the importance of the Internet in the workplace was 8.2 points (SD 1.8). Therapeutic compliance (7.0 -SD 1.8-) and patient health (7.0 -SD 1.7-) showed the best scores, and there were differences between professionals who had and had not previously participated in a telemedicine project (p < 0.05). The multivariate regression model explained the 41% of the variance for 7 factors: participation in telemedicine project (p < 0.001), quality of clinical practice (p < 0.001), patient health (p < 0.001), professional workload (p = 0.005), ease-of-use of electronic device (p = 0.007), presence of incentives for telemedicine (p = 0.011) and patient preference for in-person visits (p = 0.05). Physicians believe in the usefulness of e-health. Professionals with previous experience with it are more open to its implementation and consider that the benefits of technology outweigh its possible difficulties and shortcomings. Physicians demanded projects with appropriate funding and technology, as well as specific training to improve their technological abilities. The relationship of users with technology differs according to their personal or professional life. Although a 2.0 philosophy has been incorporated into many aspects of our lives, healthcare systems still have a long way to go in order to adapt to this new understanding of the relationship between patients and their health. The online version of this article (doi:10.1186/s12911-017-0489-2) contains supplementary material, which is available to authorized users.