Nowadays it is worldwide accepted that early diagnosis and early treatment of Rheumatoid Arthritis (RA) can improve the prognosis in most of patients. In this way, the 2010 ACR/EULAR Rheumatoid Arthritis classification criteria have shown to be more sensitive than the ACR 1987 criteria and include better patients with early RA. Other important point to focus on is to identify predictive factors for outcome, in order to propose a more aggressive treatment for early RA patients who could develop a persistent and/or erosive disease. The presence of Rheumatoid Factors (RF) and Anti- citrullinated peptides antibobies (ACPA), as well as the duration of the disease at the time of diagnosis, are independent risk factors for the development of erosive RA. As for imaging, both traditional X-ray and Magnetic Resonance Imaging (MRI) highlight respectively the Rapid Radiological Progression (RRP) and the presence of bone edema which are associated to a more aggressive disease. In the last years, the musculoskeletal ultrasonography (MSUS) has emerged as a useful imaging technique since it allows to identify synovitis and bone alteration earlier than the radiological examination. Interating clinical, serological and imaging data the clinician can define the effective disease activity of each patient.