Polyarteritis nodosa (PAN), characterized by arteritis of medium-sized blood vessels, is usually treated with a combination of glucocorticoids and immunosuppressants; however, some cases are refractory to these treatments. We herein report the case of a man with PAN that was refractory to various immunosuppressive treatments, including cyclophosphamide, methotrexate, and rituximab. After infliximab (IFX) treatment was initiated, his symptoms improved dramatically and remission was maintained. IFX is considered to be an effective alternative treatment for PAN which proves to be refractory to several immunosuppressive treatments.