The Italian Society of Rheumatology in the year 2000 decided to sponsor the creation of a data base (Registry) of consecutive patients who fulfilled the diagnosis of rheumatoid arthritis (RA) according to the American College of Rheumatology (ACR) criteria. The registry is designed to collect data on the "aggressive" type of RA all over the country in order to determine the percentage of patients who satisfy the established criteria among incident cases of RA and to define the therapeutic approach according to the characteristics of the enrolled patients. Predefined criteria set up by eight recognized opinion leaders on the disease were used by all the centers to create the database. The GIARA registry (Gruppo Italiano Artrite Reumatoide Aggressiva) has now enrolled 706 patients who will be followed up for 24 months. They have been divided into two major subsets--patients with early (< 4 months' disease duration) and late (> 4 months) RA--with the aim of establishing whether differences in clinical, serological, radiographic and therapeutic (DMARDs: disease modifying antirheumatic drugs) parameters may distinguish the two subsets. The major conclusion of this preliminary analysis is that an overall tendency to undertreatment is discernable.