For the surgical treatment of critical limb ischemia one of the decisive influencing factors for short-term and long-term limb salvage is the use of autologous veins as bypass material. There is currently a lack of studies on the long-term assessment of alternative bypass materials, which can be used for critical limb ischemia due to a lack of autologous vein material. A prospective database was established that included all patients with critical limb ischemia who received a bypass with the Omniflow-II™ prosthesis. From 2006 until 2014 bypass surgery with the Omniflow-II™ prosthesis was carried out in 123 patients. The mortality was 5 % while the morbidity was 14 % and the 5‑year survival rate was 37 %. In patients with a popliteal bypass (n = 62), the primary and secondary patency rates were 34 % and 69 %, respectively after 5 years. The corresponding results for the crural position (n = 61) over the same time period were 32 % and 34 %, respectively. After 5 years, the group receiving popliteal bypass surgery showed a limb salvage rate of 98 % whereas the crural group had a rate of 70 %. In this study we could demonstrate very promising results using the Omniflow-II™ prosthesis for the surgical treatment of critical limb ischemia.