Colorectal cancer represents the most common tumour of the gastrointestinal tract and the second most common tumour in men as well as women. The trend of increasing incidence of colorectal cancer is alerting. We undertook a retrospective study on 588 patients with rectal cancer and operated by rectal resection with anastomosis between the years 2002-2012. In our sample, we observed 54 (9.2 %) cases of anastomosis insufficiencies requiring reoperation. Out of 54 insufficient anastomoses, 36 (66 %) were in the lower two thirds of the rectum and only 18 (34 %) in the oral one. Although we have observed similar occurrences of anastomosis insufficiency in both groups - classical vs. staple suture (9.5 % and 9.0 %, respectively), the majority of stapler anastomoses (94 %) were made in the aboral part of the rectum. However, we can state that a majority of authors prefer the staple anastomosis as the one with lowest risk, mainly in the distal region of anastomosis. The high ligation of inferior mesenteric artery was performed in 182 (31 %) patients; out of these, we observed anastomosis insufficiency in 12 cases (22 %), which is exactly similar to that in the group of patients without high ligation of the inferior mesenteric artery. We did not observe the use of antibiotics in therapeutical doses as a positive factor for anastomosis insufficiencies, and neither was oncological therapy observed as a risk factor. In our group of patients we agreed that age, level of anastomosis and corticosteroids are high-risk factors. The purpose of these reports, is for the sake of future to share and reference our experiences with cases of rectal and rectosigmoideal resection over the last 11 years. We consider it important to reference our results, especially the risk factors regarding the healing of rectal anastomosis, because anastomotic healing is a surgical problem with potentially deadly consequences for patients (Tab. 4, Ref. 24).