The long-term effects of retained catheters in patients are not well known; therefore, the clinical presentation may differ. The authors present the case of a 21-year-old man with a pseudoaneurysm of the left common femoral artery, which developed 3 months after a transfemoral microcatheter embolization of a cerebral arteriovenous malformation (AVM) in which the catheter was inadvertently glued into the AVM and was retained at the groin.