Background: The aim of this study was to determine whether leakage from a colorectal anastomosis following potentially curative anterior resection for rectal cancer is an independent risk factor for local recurrence. Methods: The study included all patients who had a potentially curative anterior resection with anastomosis for adenocarcinoma of the rectum between 1971 and 1991 at Concord Hospital. The data were collected prospectively, with complete follow-up for at least 5 years. The Kaplan-Meier method was used to compare time to recurrence between strata of categorical variables. Proportional hazards regression was used in multivariate modelling. Results: There were 403 patients in the study. After adjustment for lymph node metastases, the distal resection margin of resection, non-total anatomical dissection of the rectum and the level of anastomosis, multivariate analysis identified a significant association between anastomotic leakage and local recurrence (hazard ratio 3.8, 95 per cent confidence interval 1.8 to 7.9). Conclusion: Leakage following a colorectal anastomosis after potentially curative resection for adenocarcinoma of the rectum is an independent predictor of local recurrence.