In the last decade, a new class of drugs referred to as biologics has been used successfully for treating patients with inflammatory bowel disease (IBD). Drugs such as infliximab, adalimumab, and certolizumab have been important treatment advancements because they allow the direct targeting of the inflammatory cytokine tumor necrosis factor alpha (TNF-alpha), which is elevated in the blood, stool, and tissue of patients with IBD. Evidence about the benefits of these drugs is accumulating. However, they are not risk-free, and evidence of their risks--primarily infection and malignancy--is also mounting. This article reviews that body of research and offers advice for physicians who must counsel patients about whether the benefits of these treatments outweigh the risks.