The Austrian Early Arthritis Registry (Austrian Early Arthritis Action, EAA) enrols and follows patients with inflammatory arthritis of very short (< 12 weeks) duration. Currently, data on 375 patients (almost 2000 individual follow-up examinations) have been entered into the EA database. Evaluations of data from 182 patients with a follow-up of at least one year are available. 65% of these patients have RA, as diagnosed using the ACR classification criteria in a cumulative fashion. Approximately 15% of these patients still have no established diagnosis and are being carried forward and observed as cases of "undifferentiated arthritis". In RA patients, the mean DAS 28 decreased significantly from an initial mean score of 5.5 (high disease activity) into the range of low disease activity. At the end of one year a DAS 28 of < 3.2 was observed in 52% of the RA patients. Radiological progression in these RA patients, who also received treatment very early, appears to be less severe than in other cohorts, although direct comparisons are impossible due to different methods of patient selection. In addition, the serological data from our cohort in cooperation with other study groups will allow development and validation of possible prediction algorithms for early arthritis patients which could improve the diagnostic and therapeutic approach to this patient group.