Background: This study was done to assess the relationship between the length of occlusion in infrainguinal vessels in critical lower limb ischaemia and the outcome after endovascular interventionMethods: The study was done on 40 patients presenting to the department of vascular and endovascular surgery, Kasr Al Ainy hospital, Cairo University along the period of 10/2012 to 4/2013. All patients presenting with chronic atherosclerotic critical lower limb ischemia. Endovascular intervention was our chosen approach dealing with all of the patients.Conclusion: Amputation is not significantly related to the length of occlusion so the length of occlusion is not the only factor affecting the decision of major amputation. But it should be noted that length of occlusion is significant in primary and secondary patency