Background: Peripheral arterial disease (PAD) is a common health problem and its risk is higher among patients with chronic kidney disease. The use of conventional iodinated contrast media (ICM) in angioplasty is associated with many hazards like contrast induced nephropathy and iodinated contrast allergy. The morbidity of contrast media is 5% and the mortality is 0.006%. CO2 has emerged as an alternative or adjuvant to ICM in vascular imaging, as it has many advantages. It is non-allergic, lacks renal toxicity and is a highly soluble gas. When injected into the arteries, CO2 acts as a negative contrast agent displacing the blood in the arteries and imaging devices identify the density difference between the gas and the surrounding soft tissues. The homemade plastic bag delivery system was introduced as a cheap and effective method for CO2 delivery. Aim of the work: assessment of the procedural success and complications associated with the use of CO2 angiography in endovascular treatment of chronic lower limb ischemia in patients with renal impairment or ICM allergy. Patients and methods: Thirty patients complaining of chronic lower limb ischemia, with lesions amenable for endovascular dilatation and have renal impairment or ICM allergy were treated by angioplasty using CO2 as a main contrast agent, complemented by iodinated contrast when needed. CO2 angiography was done using he homemade plastic bag delivery system. Patient demographics, clinical details, preoperative and postoperative renal function were recorded. After the procedure the patients were observed for 24 hours for any clinical incidents or endovascular complications. ABI was measured 24 hours following the endovascular procedure. All patients had regular follow up visits at one week and one month for evaluation of the procedure according to Rutherford guidelines. Results: The clinical presentation of the studied cases varied between intermittent claudication in 10 patients and critical limb ischemia in the remaining 20 patients (either as rest pain in 9 patients or trophic changes and minor tissue loss in 11 patients). The angiographic images obtained by CO2 were of accepted quality to guide the decision in angioplasty procedures in all cases. Hemodynamic success was achieved in all cases with increase of mean ABI from 0.54 ± 0.25 SD before the procedure to 0.91 ± 0.12 SD after it. The mean amount of ICM used was about 13.75 ml ± 5.58 SD and the median was 10.5 ml. Three cases, had ICM allergy, were performed exclusively by CO2 without the use of ICM. In the 30 angioplasty procedures performed, we encountered 41 arterial lesions, which were classified into iliac, femoral, popliteal or tibial regions by a percentage of 4.9%, 36.6%, 9.8% and 48.7% respectively. We succeeded to dilate 39 of those lesions, so technical and anatomical success was achieved in 95% of lesions. We had no complications related to air embolism in the studied 30 cases. As regard renal function, there was significant decrease in the mean serum creatinine value from 3.35 mg/dl ± 1.36 SD preprocedural to 3.07 mg/dl ± 1.35 SD post-procedural. Intraoperative nausea and vomiting occurred in two patients which were simply managed by antiemetic drugs with no sequel post-operatively. Conclusion: CO2 can be used as an alternative to or adjuvant to ICM in patients with renal impairment to decrease the risk of CIN associated with the use of large amounts of ICM and to prevent anaphylactic reactions that may be fatal in patients with ICM allergy. Key words: CO2 angiography - angioplasty – chronic lower limb ischemia.