Infliximab, a monoclonal anti-TNF-alpha antibody, is commonly used for treatment of moderate to severe Crohn's disease (CD). Its role in the treatment for ulcerative colitis (UC) remains controversial. We review the role of TNF-alpha in the pathogenesis of UC and describe the randomized, double-blind, placebo-controlled trials and systematic reviews that assess the efficacy of infliximab in the treatment of moderate to severe UC.