Sixty-three esophageal anastomoses were performed on adult patients with esophageal or gastric cancer. A total of thirteen anastomotic leaks occurred, resulting in death in seven patients and serious morbidity in an additional patients. Twelve patients had esophagocolostomy, with five anastomotic leaks. Four leaks occurred in the cervical region and were easily managed by local drainage and irrigation, while the other patient had an intrapleural leak resulting in sepsis and death. Twenty-eight patients had esophagogastrostomy, with a total of five leaks. All anastomoses were intrapleurally located, and death ensued in four patients. Fourteen Roux-en-Y and three loop esophagojejunostomies were performed, with no leaks. Two additional deaths occurred from leakage in the pleural cavity and left upper abdomen after jejunal interposition (3 patients) and esophagoduodenostomy (3 patients). In this study, impaired blood supply of the anastomotic end appeared to be the major cause of anastomotic failure. In addition, postoperative shock appeared to predispose to anastomotic leakage, whereas microscopic tumor at the lineof resection, duration of operation and operations for palliation did not appear to increase the leakage rate. The high mortality with esophageal anastomotic leak occurs when diagnosis is delayed and when the site of leakage is in the pleural cavity or left upper abdomen. Conservative treatment is uniformly fatal, whereas operative intervention offers the only chance for survival.