Introduction. Intraoperative anastomotic air testing of stapled colorectal anastomosis is performed by filling the pelvis with saline solution and insufflating the rectum with air through a sigmoidoscope. The presence of air bubbles indicates anastomotic leaks which are resolved during surgery. Objective. The aim of this prospective, randomized study was to perform a comparative analysis regarding the number of anastomotic dehiscences in patients checked by air leak testing and in the control group without air testing. Methods. After stapled colorectal anastomosis was performed, patients were randomized into two groups of 30 patients. The first group patients underwent intraoperative anastomotic air testing, whereas in the control group this procedure was not performed. The two groups were matched for age, sex, diagnosis and surgical procedure. Results. Intraoperative air tests were positive in seven cases and anastomotic defects were repaired. After surgery, there were three clinical leaks in this group of patients. In the control group, there were six leaks (Unilateral Fischer’s exact test, p=0.24). The incidence of colorectal anastomotic dehiscences in the study group was lower than in the control group by 50%. However, this finding was not statistically significant in our sample. Conclusion. In our opinion, intraoperative air testing of colorectal anastomosis is a good method for prevention of anastomotic dehiscence.