Objectives To assess the clinical efficacy, safety, and feasibility of autologous transplantation of mobilized peripheral blood mononuclear cells (PBMNCs) for patients with peripheral arterial occlusive disease (PAOD) of the lower extremity. Methods A total of 152 patients with PAOD of the lower extremity were enrolled into this non-controlled observational study from November 2003 to March 2006. All patients received subcutaneous injections of recombinant human granulocyte colony-stimulating factor (G-CSF, 450600 μg/day) for 5 days in order to mobilize stem/progenitor cells; their PBMNCs were collected and transplanted by multiple intramuscular injections into ischemic limbs. Patients were followed up for at least 12 weeks. Results At 12 weeks, primarymanifestations,including lower limb pain and coldness, were significantly improved in 137 (90.1%) of the patients; limb ulcers improved or healed in 46 (86.8%) of the 53 patients, while 25 of the 48 (47.9%) patients with limb gangrene remained steady or improved. Ankle-brachial index (ABI) improved in 33 (22%) of the cases, and TcPO2 increased in 45 (30%) of the cases. Angiography before treatment, and at 12 weeks after treatment, was performed in 10 of the patients and showed formation of new collateral vessels. No severe adverse effects or complications specifically related to cell transplantation were observed. Conclusion Autologous transplantation of G-CSF-mobilized PBMNCs might be a safe and effective treatment for lower limb ischemic disorder.(J Geriatr Cardiol 2006; 3:178-80.)