Objective To investigate the measures to prevent the anastomotic leakage following anterior resection of rectum. Methods A series of seventy-four patients with rectal cancer undergoing anterior resection from January 1991 to October 1998 were analyzed.Results The clinical anastomotic leakage rate was 4.05 per cent (3/74). The causes of leakage were presacral infection and insufficiency of blood supply in incisional margin. Conclusion The proximal colon must be completely mobilized and blood supply of incisional margin should be sufficient. Persistent postoperative presacral suction must be performed to protect fluid accumulation resulting in infection. Intracolonic drainage is an important factor in prevention of anastomotic leakage. Temporary stoma is not necessary.