Objectives To assess relationship between body mass index (BMI) and efficacy of tocilizumab (TCZ) in rheumatoid arthritis (RA) patients. Methods We conducted a retrospective study of the use of TCZ in patients with RA followed by five academic hospitals in France. The efficacy of TCZ was evaluated at 6 months by the European League Against Rheumatism (EULAR) response. Univariate and multivariate logistic regressions were performed adjusting for age, sex, disease duration, C-Reactive protein, erythrocyte sedimentation rate, presence of erosive lesions, rheumatoid factor and anti-citrullinated peptide antibodies positivity, disease duration, disease activity score, concomitant therapy by disease modifying anti-rheumatic drugs. Results Among 222 RA patients treated by TCZ, 58.5% had a low BMI<25kg/m2, 26% had an intermediate BMI between 25-30kg/m2, and 15.5% had a high BMI>30kg/m2. No significant association between BMI and response to TCZ at 6 months was found after adjustment for potential confounding factors (OR 0.47; 95%CI [0.18; 1.23], p=0.12 and OR 1.56 95%CI [0.42; 5.67], p=0.49 for BMI=25-30kg/m2 and BMI>30kg/m2 respectively compared to BMI<25kg/m2). Conclusions Response to TCZ in RA patients is not influenced by the baseline BMI, in contrast to anti-TNF drugs. Future research should assess these differences prospectively for better comparisons. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.1508