Background: Ciclosporin has proven to be effective in patients with corticosteroid-refractory ulcerative colitis (UC). When therapy with this drug fails, infliximab can be considered to avoid colectomy. The efficacy and safety of this sequential approach remain unknown. Aim To assess the efficacy and safety profile of treatment with infliximab after failure of ciclosporin in patients with a corticosteroid-refractory flare of UC. Methods Retrospective review of medical records of patients with a corticosteroid-refractory flare of UC who did not respond to ciclosporin and received salvage therapy with infliximab within a month of discontinuing ciclosporin. The severity of the flare and response to the treatment were graded using the Lichtiger index. Cumulative rates of colectomy were calculated using Kaplan-Meier analysis. Cox regression analysis was performed to identify predictors of colectomy. To evaluate the safety profile of this treatment strategy, any adverse event occurring after the first infusion of infliximab was considered. Results The study population comprised 47 patients with corticosteroid-refractory UC treated with infliximab after failure of ciclosporin. The median baseline Lichtiger index was 13. The mean time from the last ciclosporin dose to the first infliximab infusion was 6 days. After the first infliximab infusion, 13% of patients achieved remission, and 74% partial response. Of the 35 patients who received the third infliximab infusion, 60% achieved remission, and 37% partial response. Fourteen patients (30%) underwent colectomy. The rate of adverse events was 23%. One death occurred in a 40-year-old man who failed ciclosporin and infliximab and underwent surgery 10 days after the first infliximab infusion; he died of nosocomial pneumonia. Conclusions Treatment with infliximab makes it possible to avoid colectomy in two-thirds of corticosteroid-refractory UC patients in whom ciclosporin fails. However, the rates of adverse events and mortality mean that the decision to administer sequential therapy (ciclosporin-infliximab) should be taken on an individual basis. © 2011 Blackwell Publishing Ltd.