Background : An acute infusion reaction during infliximab infusions could lead to drug withdrawal and limit the therapeutic armamentarium in inflammatory bowel diseases Aim : To determine the risk and protective factors of an acute infusion reaction. Materials and methods : Data were retrieved retrospectively from electronic charts of patients from the 'Clermont-Ferrand IBD cohort'. Results : Among 80 patients, including 51 (63.8%) patients with Crohn's disease, 23 (28.8%) experienced an acute infusion reaction. In multivariate analysis, the Crohn's disease nonstricturing nonfistulizing phenotype predicted an acute infusion reaction (odds ratio= 11.40, 95% confidence interval 1.5-87.6; P= 0.019). Among 1107 infusions, we observed 38 acute infusion reactions (3.4%). In multivariate analysis, only resumption of infliximab after drug holiday was a major risk factor (odds ratio= 24.87, 95% confidence interval 4.4-140.0; P< 0.001). Concomitant premedication or immunosuppressant therapies did not prevent an acute infusion reaction. The patients who experienced an acute infusion reaction had a trend toward a higher rate of infliximab discontinuation (69.6 vs. 50.9%, P= 0.14). Conclusion : An acute infusion reaction is a major event in the history of inflammatory bowel diseases patients treated with infliximab as it could lead to drug discontinuation and thus limits the therapeutic armamentarium considerably. The resumption of infliximab after drug holiday is a major risk factor for an acute infusion reaction. Premedication efficacy remains questionable and should be limited to these high-risk patients.