Since 2004 an electronic epidemiological surveillance system (AVE) has been developed and implemented for infectious diseases in the autonomous region of Valencia that allows data collection from notifiable diseases in real time concerning outbreaks and alerts, as well as analysis and dissemination of the information. Within the autonomous region of Valencia, the system is used by 17 epidemiology units, which act as the first level of specialized surveillance. The electronic surveillance system is used by all these units, as well as by physicians working in primary and specialized care, who can introduce information from the ambulatory information system while the patient is in the practice room. The system is able to capture the demographic data from the patient and the physician can add any other information that is considered important for the case detected. The system receives new laboratory test results overnight from the Microbiological Surveillance Network (RedMIVA). AVE can record outbreaks of notifiable diseases as well as any unusual clusters or changing patterns of any disease. The department of epidemiology has access to the whole system for analysis of the information and for quality control of the epidemiological surveillance. The system provides timely and comprehensive information to facilitate public health action in individual cases of infectious disease.