We present the case of an 18-year-old woman with Crohn's disease manifested by diffuse abdominal pain, bloody diarrhea accompanied by arthralgia, and swelling of large joints. On the lateral aspect of her right ankle there was an hemorrhagic, necrotic bullous lesion measuring 3 x 4 cm, surrounded by cutaneous inflammation and erythema. Biopsy showed a neutrophilic abscess-like ulcerative skin inflammation, which was diagnosed as pyoderma gangrenosum. The patient was treated with high doses of parenteral methylprednisolone, but her condition failed to improve and infliximab, a TNF-alpha blocking agent, was instituted. An immediate response of Crohn's disease was observed and, over the next 5 weeks, the ulcer on her right ankle also healed completely.