In a series of 132 patients who had undergone surgical treatment for carcinoma of the esophagus and upper part of the stomach, anastomotic leakage occurred in 29. We retrospectively studied the factors that could influence the healing of the fistulas in the management of this condition. Despite adequate supportive treatment, including total parenteral nutrition, five patients died from unrelenting infection. Fifteen fistulas closed spontaneously after an average of about four weeks of conservative treatment and full nutritional therapy. Those patients who had persistent fistulas after similar treatment were found to have either residual tumor after palliative operation or preoperative serum albumin levels that were lower than those of the other group. Prolonged conservative treatment for persistent fistulas may not be warranted if such risk factors are identified, and surgical repair should be considered.