Over the last decade information and communication technologies - telematics technologies - have demonstrated their potential to improve the quality, access and efficiency of health care. Health telematics applications are presently revolutionizing the developments not only in diagnosis, treatment, surveillance and rehabilitation of patients, but also on the side of the more collective aspects of health care and health prevention such as clinical trials, epidemiology and health education. Moreover, for the first time in the history of health care the emerging Health Information Infrastructure (HII), i.e. telematics networks together with a set of technologies, health telematics applications and services, is making possible the rapid dissemination and sharing of health information and research results. This is leading to knowledge creation and to promotion of innovative approaches based on evidence collected in medical practice all over the world.