<h3>Background</h3> Remission or low disease activity is the therapeutic target of rheumatoid arthritis (RA). There is a consistent body of evidence supporting the value of ultrasound (US) findings in the diagnosis, disease activity and treatment monitoring of RA patients. In spite of these pieces of information, the real impact of US in treatment decisions in patients has not yet sufficiently studied. <h3>Objectives</h3> To explore the impact of US findings, in terms of proportion of patients in whom treatment recommendation differed after the US examination, in RA outpatients. We also tested the variations of US impact according to the level of patient9s disease activity or the physician9s experience. <h3>Methods</h3> Thirty-five consecutive outpatients were included. In the 1st step a senior rheumatologist (SR) and a trainee in rheumatology (TR), blinded to each other evaluations performed a clinical evaluation including DAS28, then, they independently proposed a treatment recommendation. In the 2nd step, all patients underwent an US examination using the 7-joint US score (2) by an experienced rheumatologist blinded to clinical evaluation, in order to established the sonographic disease activity. In the final step, all the patients returned to both, the SR and the TR, who integrated the US findings to their previous evaluation and reviewed their prescription. Potential changes of treatment (pre- and post-US) between both physician9s (SR and TR) were recorded on standardized formats. Patients received final recommendation only from the SR. US usefulness was separately evaluated by the SR and the TR according to a Likert scale (0= not useful at all, 10= very useful). <h3>Results</h3> Patients were mainly female (91.4%), with (mean±SD) 44.8±10.1 years of age and (median, Q25-Q75) disease duration of 6.5 years (2.9–11.2). Fifty-one (73%) patients were in DAS28-remission and 29 (27%) showed some disease activity. In 17 clinical evaluations (25%), data from US evaluation modified treatment and it was most frequently increased (64.7%). Interestingly, DAS28 was higher in clinical evaluations where US impacted treatment than in those where US did not: (median [Q25-Q75] DAS28: 2.6 (1.6–3.2) vs. 1.6 (1.1–2.2), p=0.009. Also, there was a higher proportion of active patients among the first group: 47% vs. 20.7%, p=0.06. Twelve of the 17 clinical evaluations where US modified treatment recommendation, were performed by TR vs. 5 performed by the SR: 71% vs. 29%, p=0.09; nonetheless, US usefulness was equally scored by both physicians: 3 (2–7) vs. 3 (2–5), p=0.5. <h3>Conclusions</h3> US was an important technique for the treatment decision in routine clinical practice of patients with RA; the impact of US was more frequent in patients with active disease and in TR. <h3>References</h3> Joshua F et al. Summary findings of a systematic review of the ultrasound assessment of synovitis. J Rheumatol 2007;34: 839–47. Backhaus et al. Evaluation of a novel 7-joint ultrasound score in daily rheumatologic practice: a pilot project. Arthritis Rheum. 2009;61: 1194–201. <h3>Disclosure of Interest</h3> None declared