Background: Anastomotic leakage remains a major complication after large bowel surgery. Chronic obstructive pulmonary disease is frequent disease in the elderly. Aims: The authors want to analyze the correlation between systemic tissue hypoxia, resulting from chronic obstructive pulmonary disease and anastomotic leakage in large bowel surgery in a group of patients over 65 years. Patients and methods: In the period 1979-2001 at our surgical Department, 590 patients underwent colorectal surgery; 211 elderly patients (>65 years) with large bowel anastomosis were selected. In 29/211 (13.7%) chronic obstructive pulmonary disease was diagnosed. The group of patients affected by chronic obstructive pulmonary disease was defined as group A; the other, as group B. The incidence of anastomotic leakage in patients with and without chronic obstructive pulmonary disease was evaluated. Results: The overall incidence of anastomotic leakage was 5.6% (12/211); a difference in the incidence of anastomotic leakage was found in the group A vs. B: 7/29 (24.1 %) in the group A were affected by dehiscence vs. 5/182 (2.7 %) of group B. This difference was statistically significant (p = 0.001). Conclusions: Chronic obstructive pulmonary disease can be a factor increasing the risk of anastomotic leakage. The elderly patient is often affected by chronic obstructive pulmonary disease and consequently show an higher risk of colonic anastomostic failure than younger patients.