BACKGROUND Although saphenofemoral junction aneurysms are not so rare, only scarce of the published cases reported thrombosis of the aneurysmal sac and saphenous trunk. METHODS A 65-year-old male with varicose disease, developed acute ascending superficial vein thrombosis of the left greater saphenous vein, involving the 6-cm saphenofemoral junction aneurysm. The patient underwent common femoral vein thrombectomy, aneurysm removal, and greater saphenous vein excision with uneventful postoperative course. CONCLUSIONS Thrombosed giant saphenofemoral junction aneurysms require emergent surgical intervention aimed at preventing potential progression to deep vein thrombosis and pulmonary embolism.