Polyarteritis nodosa (PAN) is a systemic vasculitis involving small- and medium-sized arteries, which presents with necrotizing inflammation. PAN occurs as a systemic disease or as a limited form confined to a single organ. Few cases have been reported with single organ involvement, and even fewer have been reported with skeletal muscle involvement. Herein, we report the ultrasonography and magnetic resonance imaging findings in a rare case of PAN with limited muscle involvement in a 66-yearold man.