Long-term effects of autologous mononuclear bone marrow cell transplantation were studied in patients with severe peripheral arterial disease (PAD) and critical limb ischemia. Ten patients with end-stage disease were infused twice with autologous bone marrow cells and they completed the 12-month follow-up study. Substantial improvement of blood flow and increasing capillary densities were seen when compared with a concomitant control group comprising patients who did not enroll in the study. The ankle-brachial index (ABI) and pain-free walking distance improved significantly in treated patients. The improvement was sustained 12 months after treatment. These results confirm that the autologous bone marrow transplantation is an effective therapeutic strategy in critical limb ischemia.