Objective: To evaluate the effect of the treatment of infected femoral artery pseudoaneurysm using bypass grafting with vascular prosthesis. Methods: The clinical data of 40 patients with infected femoral artery pseudoaneurysm admitted to our hospital from January 2005 to December 2010 were analyzed retrospectively. All the 40 patients were drug abusers, and underwent pseudoaneurysm excision, radical debridement and vascular prosthesis bypass grafting operation. Results: No death occurred and the patients′ limbs were all successfully salvaged during the perioperative period. All wounds were healed by secondary intervention. Thirty-four patients were followed up for 3 to 12 months (average of 7.4 months). Prosthetic graft infection occurred in three patients (8.8%) during the follow-up period, two of whom had their limbs salvaged after removal of the infected graft, and one finally underwent amputation because of ischemic limb necrosis. Thrombus formation was detected by color Doppler ultrasound in some parts of the lumen of prosthetic graft in four patients (11.8%), however, no ischemic necrosis occurred in the affected limbs of the four patients after antiplatelet therapy. Conclusions: Bypass grafting using vascular prosthesis is a safe and effective method for treatment of infected femoral artery pseudoaneurysm secondary to illegal drug injections.