BACKGROUND The aim of this study was to evaluate early and one-year outcomes of urgent endovascular treatment in patients with acute on chronic critical limb ischemia (CLI). METHODS Between January 2012 and December 2013 104 patients with acute on chronic CLI (Rutherford class 4-6) were referred to two tertiary hospitals. In all cases the urgent endovascular revascularization was considered the first therapeutic option. Twenty-seven patients (26%) were excluded from this approach (long occlusion >30 cm of the femoro-popliteal tract and/or massive gangrene with abscess/osteomyelitis/necrotizing fasciitis). RESULTS Seventy-seven out of 104 patients received an urgent endovascular treatment. They were predominantly male (43, 55.8%) with a mean age of 76.5 years (range 47-94). In 67 cases (87%) the patients had leg/foot lesions (54, 70.1%, Rutherford class 5, and 13, 16.9%, Rutherford class 6). During the follow-up (mean duration 6.2 months, range 1-24 months) the healing of the lesions and the relief of rest pain were obtained in 46 cases (59.7%). Estimated one-year primary patency, primary assisted patency, secondary patency, and limb salvage rates were 63.6%, 68.3, 69%, and 84.1%, respectively. At uni- and multivariate analysis patients in Rutherford class 6 showed poor results in terms of primary patency, primary assisted patency, secondary patency, and limb salvage (P<0.001). CONCLUSIONS Urgent endovascular treatment in selected patients with acute on chronic CLI represents a safe and effective option with good results in terms of healing of the ischemic lesions, relief of rest pain, and limb salvage. Patients in Rutherford class 6 showed fewer benefits with this approach.