Introduction : Femoral artery pseudoaneurysm is a serious, but rare, complication of endovascular treatment. This case illustrates the rapid evolution of a large, symptomatic pseudoaneurysm in a high-risk patient and emphasizes the importance of urgent surgical treatment. Case Presentation : A 45-year-old south Asian man with a history of type 2 diabetes, hypertension, dyslipidemia, and prior ischemic stroke came to the emergency department with right groin pain and rapidly increasing swelling four days post left internal carotid artery stenting through right femoral access. Physical examination identified a pulsatile mass with overlying bruit. CT angiography indicated a large hematoma with extravasation of active contrast from the right femoral artery. Because of the hematoma size and active bleeding, the patient was taken for emergent surgical exploration, evacuation of a 1 kg clot, removal of the pseudoaneurysm sac, and primary repair of the arterial defect. His postoperative course was uneventful with preserved limb perfusion and successful discharge. Conclusion: This case highlights the fact that significant, growing pseudoaneurysms with ongoing extravasation usually need to be treated with definitive open surgical intervention. It underlines the need for close post-procedure monitoring, particularly in high-risk patients on antithrombotic therapy, and the necessity of having a low threshold for imaging and surgical referral.