We described a 37-year-old man with Crohn's disease (CD) resembling systemic lupus erythematosus (SLE) at his disease onset. He was admitted to the municiple Akiru Hospital in October 1986 by fever, aphtous oral ulcerations, sore throat and polyarthralgia. Hematologic examination showed leukocytopenia, lymphocytopenia, positive tests for antinuclear antibody, anti-DNA antibody and LE cell phenomenon. He has had episodes of convulsion and conciousness loss of unknown etiology when he was 17 years old. The diagnosis of SLE was made, and oral medication of prednisolone was started. Several weeks later, most of symptoms and autoantibodies disappeared, although the oral aphtous ulcerations and leukocytopenia remained. In May 1987, he admitted to the other hospital because of bloody vomiting. Endoscopic examination showed the esophagial ulceration, and histology of biopsied-specimen was nonspecific esophagitis. The combination of prednisolone and oral cyclophosphamide or methotrexate was employed thereafter. However, the leukocytopenia, oral aphtous ulceration and esophagial ulceration continued in spite of these treatments. All the immunosuppressive treatment was stopped at March 1992. In October 1995, he admitted to our hospital because of body weight loss and continuous diarrhea with occasional bloody stool. Barium enema and endoscopic examination of the colon revealed the findings compatible with CD. The patient responded favorably to methylprednisolone pulse therapy followed by oral sulphasalazine. This case indicated that cases with inflammatory bowel diseases like CD could show similar clinical signs and symptoms to SLE, and in some cases of CD might satisfied the classification of criteria for SLE.