EXTERNAL iliac artery intimal fibrosis is an uncommon entity that causes transient lower extremity ischemic symptoms in well-trained athletes, particularly cyclists. Diagnosis requires a high index of suspicion and is supported by noninvasive vascular duplex examination. Angiographic findings, however, can be subtle and may be overlooked. We describe the use of intravascular ultrasound (IVUS) for diagnostic confirmation of this entity.