External iliac vein stenosis owing to prolonged cycling.

Prolonged cycling has previously been associated with external iliac artery stenosis, termed "cyclists' iliac syndrome." However, no association between external iliac vein stenoses and cycling has been previously described. We describe a unique case of a 70-year-old cyclist presenting with an iliofemoral deep venous thrombosis owing to an external iliac vein stenosis. This is the first case of a potential association between cycling and iliac vein stenosis. Further study and follow-up will be required to assess whether angioplasty and stenting is the optimal method of therapy for iliac vein stenoses owing to cycling.