Femoral pseudoaneurysm is a serious complication in drug addicts who habitually inject via the groin. A total of 33 drug addicts presenting with 34 infected femoral pseudoaneurysms were treated in the Department of Surgery, the University of Hong Kong, Queen Mary Hospital from July 1993 to June 1996. There were 27 men and 6 women, with ages ranging from 23 to 76 years (mean 39.6 years). Positive intraoperative tissue cultures were seen in 29 (85%), with 17 being pure growth of methicillin-sensitive Staphylococcus aureus (MSSA). Twenty-four pseudoaneurysms involved the femoral bifurcation and were treated by triple ligation of the common femoral, superficial femoral, and profunda femoris arteries. Seven other limbs underwent ligation of the common femoral artery alone, and three had superficial femoral artery ligation. Nineteen limbs had the external iliac artery ligated in addition to the femoral ligation for better proximal control. The mean postoperative ankle-brachial index (ABI) was 0.43 and 0.52 in those with triple ligation and those with single-vessel ligation, respectively. There was no hospital mortality, and all patients were discharged with a viable limb. The duration of follow-up ranged from 2 to 36 months (mean 15.5 months). Four patients were asymptomatic, but the rest suffered some degree of intermittent claudication. No delayed limb loss was identified. We conclude that systemic antibiotics active against MSSA are the antibiotics of choice in drug addicts with infected femoral pseudoaneurysms. Ligation and excision of the pseudoaneurysm without revascularization is safe, with acceptable morbidity and a low limb loss rate.