A traumatic venous aneurysm within the greater saphenous vein occurred in a 15-year-old hockey player. The patient had early diagnosis and surgical excision of the lesion. Venous aneurysm is a rare clinical entity and a pathologic curiosity in the absence of varicose veins. It can lead to serious complications, such as pulmonary embolism, portal hypertension, and rupture. Early diagnosis with the use of venography and surgical excision of the lesion can prevent major complications.