In 2000-2003 surgeons performed 616 surgeries on arterio-venous access formation, more than 30% of them were radiocephalic. In 36.9% of cases of radiocephalic fistula early thrombotic complications developed (during the first month after operation) and a new access creation was needed. Various factors that indicate early thrombotic complications in radiocephalic fistula were assessed. 146 case records were analyzed retrospectively and all patients were divided into two groups. The first group (n=94) consisted of the patients with normal function of radiocephalic fistula; the second group (n=52) was comprised of patients in whom thrombotic complications developed during the first month after surgery. Comparison of the groups showed that the main disease, patients age, gender and technique of operation (all surgeries were performed using microsurgical technique, but accesses were formed "end to end" or "end to side" using 7/0 or 8/0 sutures), did not influence the development of early thrombotic complications in radiocephalic fistula. The shorter time of maturation of new access was associated with more frequent early thrombotic complications: the mean time of new vascular access maturation was 15.45+/-2.56 days in the first group, and 12.5+/-2.42 days in the second group (p<0.05). A marked tendency of more frequent early thrombotic complications was noticed in patients older than 60 years and in patients with ischemic heart disease.