There is recent evidence from clinical trials that implantation of stem/progenitor cells improve limb ischemia. In the present study implantation of autologous peripheral blood mononuclear cells (PBMNCs) mobilized by granulocyte-colony stimulating factor (G-CSF) - investigated in patients with chronic limb ischemia.Twenty-four patients with chronic lower limb ischemia were enrolled and randomized (1:1) to either the implanted group or the control group. In the implanted group, the patients received subcutaneous injections of recombinant human G-CSF (300μg/day) for 5 days to mobilize stem/progenitor cells, and their PBMNCs were collected and implanted by multiple intramuscular injections into ischemic limbs while control group injected by sterile saline and receive medical treatment. All of the patients were followed up after at 12 week.At the end of the follow-up period, the main manifestations were significantly improved in the patients of the implanted group compared to the control group. Mean of rest pain decreased from 6.42±2.15 to 1.67±3.89 (P<0.001). Mean of pain free walking distance increased from 25±29 to 409±204 (P<0.001). Mean ankle-brachial pressure index increased from 0.45± 0.32 to 0.79± 0.38 (P = 0.005). A total of 7 of 9 limb ulcers and wounds (77.8%) of implanted patients healed after cell implantation. Two lower limb amputations occurred in the implanted patients. In contrast, eight control patients had to receive a lower limb amputation.