Work from Polish colleagues Barc and coworkers report promise with a novel gene therapy approach. Critical leg ischemia (CLI) complicated by diabetes mellitus (DM), which is a very common and dangerous disease, represents the ultimate stage of peripheral arterial disease. Patients are treated with antiplatelet drugs, statins and limb revascularization, but a significant number of patients are not candidate for revascularization. Literature shows that in such cases, gene therapy could be a perfect therapeutic option. The aim of our study was to evaluate efficacy of double vascular endothelial growth factor/hepatocyte growth factor (VEGF/HGF) gene therapy in patients with CLI complicated by DM. We observed that 90 days after administration, serum level of VEGF and ankle-brachial index increased significantly (p < 0.001) and rest pain decreased significantly compared with the control group (p < 0.002). Moreover considerable improvement in vascularization was observed in computed tomography angiography (P = 0.04). Based on the results of this study, we suggest that the therapy with pIRES/VEGF165/HGF bicistronic plasmid administration is a safe and effective method of treatment of patients with both CLI and DM.