Since 1998, the Epidemiological Survelliance System of Navarra has included the notification of 34 transmissible infectious diseases, to which are added epidemic outbreaks of any aetiology and cause. Reporting to the system is carried out on a weekly basis by every doctor who suspects, or diagnoses, any of these processes. In our autonomous community, Diseases of Compulsory Notification (DCN) are reported using standardised forms on a weekly basis to the Section of Infectious Diseases and Control of Outbreaks of the Public Health Institute. Notification is made by the doctors and/or paediatricians of Primary Care and by certain services of Specialised Care. Subsequently, the information is sent to the National Epidemiology Centre where data from the Autonomous Communities is centralised and diffused. The year 2002 marks the fifth year of the new Epidemiological Vigilance System. In these five years there have been 74,814 notifications of disease, 17,184 in the year 2002, which provides a balance of notification of 74.07% for this year. In 2002, under the heading of respiratory transmitted diseases, 24,870 cases of Inluenza were reported, Epidemic Index (EI: 0.80). 58% of total annual cases were reported in the first nine weeks of the year, with a maximum in week 4 when 3,277 cases were reported. 16 cases of Meningococcal Disease were reported to the system (EI: 1.07). All the cases were confirmed microbiologically and all appeared in a sporadic way. With respect to the causative serogroup, on 12 occasions Neisseria meningitidis serogroup B was isolated and in the 4 remaining cases serogroup C was isolated. One case was notified in infants of less than 2 years of age (Rate: 10.52 cases per 100,000), another case in children between 2 and 5 years (5.52 cases per 100,000), 5 cases in the age group of 6 to 19 years (Rate: 5.86 cases per 100,000) and the remaining nine cases in the age group of persons aged 20 years or over (2.2 per 100,000). 70 cases of Legionellosis were declared in 2002 (EI: 4.67), all but one under the clinical form of pneumonia. Twenty-two of the cases were presented in the context of two outbreaks with a community origin, which affected 17 and 5 persons respectively. Similarly, there was a notable increase in the declaration of cases of bacillary dysentery, with 6 cases (EI: 2.00), brucellosis, with 10 cases (EI: 1.67) and chickenpox, with 4,346 notified cases (EI: 1.61).