Takayasu arteritis (TA) and inflammatory bowel disease (IBD) are chronic inflammatory disorders. The mechanisms underlying these diseases are not precisely known, but tumor necrosis factor alpha (TNF-α) is considered to have an important role in the pathophysiology of both TA and IBD. Simultaneous occurrence of both TA and IBD is rare. Our first case was a 42-year-old woman with TA and inflammatory bowel disease unclassified. The patient was refractory to treatment with an immunomodulator, and infliximab (IFX) was started. After starting IFX, clinical remission was achieved and maintained for 2 years. The second case was a 34-year-old woman with TA accompanied by Crohn’s disease. Because her abdominal symptoms relapsed despite treatment with an immunomodulator, IFX was started. Both diseases were well controlled for 2 years by scheduled maintenance therapy with IFX. Relapse of the TA required increased doses of IFX at shorter intervals, which relieved her symptoms. Overall, we identified nine cases for which IFX was effective, including our 2 cases. They may demonstrate the efficacy of IFX for IBD with TA and emphasize the role of TNF-α in the pathophysiology.