Background: Patients with critical limb ischemia (CLI) who are not candidatefor surgical or percutaneous revascularization carry a poor prognosis. Stem cellinjection is emerging as a novel therapy in those patients. Stem cell injection aimat critical limb salvage through improving peripheral vascular collaterals.Patients and Methods: Thirty patients were included in the study and dividedinto 2 groups. Group 1 patients (active treatment group, n=15) were subjected toautologous bone marrow injection into their critical limbs. Group 2 patients(control group, n=15) were observed for the natural history of their critical limbs.Patients were followed up for 6 months for subjective and/or objective evidenceof vascular improvement.Results: The mean amount of injected bone marrow-mononuclear cells (BMMNC)was (67.1 + 33.7 x107 /ml), of which (94.1 + 2.7%) were viable cells. Themean CD34+ cells was (4.5 + 1.0%), mean CD133+ cells was (2.1 + 0.5%) andmean dual CD34+ CD133+ cells was (1.2 + 0.2%). After 6 months follow up,there was no significant difference in the clinical outcome or ankle brachial index(ABI) between the two studied groups. Three patients in each group showedclinical vascular improvement. Seven patients in each group were amputated(median time to amputation was 30 days for group (1) patients and 21 days forgroup (2) patients, p value was 0.4). Three patients in group 1 and two patients ingroup 2 died before completing the follow up period.Conclusion: This study shows that injection of autologus BM-MNC in patientswith "no-option" CLI was a safe and feasible procedure. Yet, its therapeuticbenefit could not be demonstrated. It's noticeable that all patients who improved(3 patients in each group) were at a lower (less than category 6) Rutherford grade.Larger placebo-controlled studies are needed to verify these findings.