Twenty-five patients ASA II-IV suffering from diabetic foot that were previously scheduled for debridement or amputation (lower than the ankle) were recruited to receive the sciatic and femoral nerve block. All of the patients were placed supine, with the head of bed at an elevation of 30-45A degrees. Sciatic and femoral nerves were blocked by the injection of 10 mL of 0.5 % ropivacaine into two sites using ultrasound guidance. The first site was 7-9 cm above the popliteal fossa, and the second site was in the middle of the groin. All 25 cases obtained a satisfactory analgesia effect. The mean total procedure time of the sciatic and femoral nerve block was less than 10 min (8.3 +/- 2.7 min). The sensory onset time was 16.3 +/- 6.5 min, and the duration of sensory block was 586 +/- 144 min. The motor onset time was 28.6 +/- 13.7 min, and the duration of motor block was 498 +/- 255 min. None of the patients required additional analgesics. No remarkable circulatory or respiratory changes related to anesthesia were observed. Four of the patients exhibited nausea and vomiting and were treated effectively with 4 mg ondansetron i.v. One patient complained of weakness in the affected lower limb 2 days after surgery yet fully recovered the next day without any treatment. Our pilot study indicated that ultrasound-guided femoral and sciatic nerve block in supine position for surgical management of diabetic foot in critical patients is a safe and efficacious approach.