Electronic cigarettes (e-cigarettes) have attracted considerable attention as a possible alternative to tobacco cigarettes, but uncertainties about their impact on health and indoor air quality as well as their commercial success without a clear regulatory framework are arousing concern. We have therefore tried to summarize the health-related implications of the use of e-cigarettes in order to help physicians and health professionals provide accurate information on this device. Given the lack of unequivocal scientific data on their toxicity and safety, we conclude that at the moment there is no reason to approve e-cigarettes as a safe alternative to tobacco smoke.