ABSTRACTA 28-year-old male patient was admitted to the Orthopedic Service for a joint biopsy due to significant swelling in the left knee. He had a history of laparotomy for multiple gunshot wounds one year earlier, a mass in the left knee with severe pain, joint retraction, and gait limitation. Physical examination revealed a giant and reluctant mass in the left suprapatellar region. The tomographic study with vascular contrast showed a decrease in the caliber of the left superficial femoral artery in its distal portion prior to the emergence of the adductor canal, secondary to a large mass in the posterior compartment of the ipsilateral thigh. Arteriography showed a pseudoaneurysm of the left popliteal artery with a significant decrease in the caliber of the left superficial femoral artery. A firearm projectile was identified in the right knee. It was treated with open surgery and cell salvager Medtronic®, the pseudoaneurysm was resected, and raffia of the popliteal vein and arterial reconstruction with polytetrafluoroethylene prosthetic graft was performed.