The objective — of the present work was to develop the forensic medical criteria for the evaluation of the unfavourable outcomes of the roentgeno-endovascular operations (REVO) on the arteries of the lower extremities. The study included the analysis of the conclusions based on the results of the commission forensic medical examinations, attorney inquiry reports, query response, medical histories of the hospitalized patients who had undergone the roentgeno-endovascular operations on the arteries of the lower extremities. The criteria for the forensic medical evaluation of the unfavourable outcomes of the roentgeno-vascular operations on the arteries of the lower extremities have been proposed together with the indications for REVO, methods and tools for the performance of these surgical procedures. Particular attention was given to the identification of the signs and prognostics of the unfavourable outcomes of the roentgeno-endovascular operations (both intraoperatively and during the early postoperative period and the subsequent stay in the hospital) and to the risks of the development of the unfavourable outcomes of the surgical interventions following the technically adequate REVO. Special emphasis is placed on the cause-and-effect relationship between the actions or a failure to act on the part of an emergency physician and/or an attending surgeon/cardiovascular surgeon and the possibility of the unfavourable outcomes of the roentgeno-endovascular operations.