Infliximab is a novel biologic agent developed from recombinant technology now used widely in the treatment of Crohn's disease. It is effective in inducing and maintaining response in patients with moderate to severe luminal and fistulizing disease refractory to conventional therapy. Infliximab has also been shown to have a steroid-sparing effect. Although safe and generally well tolerated, the drug carries side effects that clinicians need to be able to recognize and to manage properly. Studies are underway to determine the best strategies to avoid antibodies to infliximab and to refine use of the agent.