Aim of the investigation. Evaluation of significance of a number of clinical predictors of complicated course of perioperative period in patients with rectal cancer and rectosigmoid junction. Materials and Methods. Retrospective analysis of 170 patients with rectal cancer or rectosigmoid junction. Patients with adenocarcinoma of rectum or rectosigmoid junction which were operated in combination to partial or total mesorectumectomy were included to the study. In all cases an anastomosis was formed. There were 54.7% of men and 45.3% of women. The mean age of the patients was 63 years. Preoperative treatment was performed in 54 patients. Influence of various factors (gender, age, BMI, anatomical risk factors, neoadjuvant therapy, type of operation, ligation level of the inferior mesenteric artery, forced mobilization of the splenic flexure of the colon, surgical access, anastomosis type, anastomosis protection, duration of operation, preventive stoma) on the risk of perioperative complications and separately inconsistent anastomosis suture was estimated. Results. Neoadjuvant chemoradiotherapy increases the risk of intraoperative complications by 3.4 times. Risk of anastomosis inconsistency is 3,35 times increased in men, 2,6 times for forced mobilization of the splenic flexure of the large intestine and 10 times for intraoperative perforation of the large intestine. Predictors of complicated course of the postoperative period are adhesions, narrow pelvis, short mesentery of the sigmoid colon, dolichosygma (p<0,05). Conclusion. Presence of the above risk factors must lead to application of measures on prevention and elimination of consequences of perioperative complications.