Case: This report describes a 25-year-old female professional triathlete with right external iliac artery endofibrosis (EIAE) that was definitively diagnosed on contrast-enhanced magnetic resonance images obtained immediately after treadmill running. The EIAE was treated by percutaneous transluminal angioplasty. By 8 weeks after surgery, she had no symptoms of claudication or pain in the right thigh after a 1-hour running session. There has been no recurrence in 1 year postoperatively.

Conclusion: EIAE is a rare condition and difficult to diagnose in a timely manner because symptoms and radiographic imaging features appear only during intense exercise. Our patient was successfully treated with percutaneous transluminal angioplasty.