From July 1982 to June 1985, 100 patients with squamous cell carcinoma of the thoracic esophagus had esophageal resection and reconstruction using an abdominal and right thoracotomy approach (Lewis-Tanner operation). Five patients died within 30 days. The remaining 95 patients were studied prospectively for evidence of local recurrences. It was found that anastomotic recurrences occurred in eight patients, and mediastinal recurrences involving the intrathoracic stomach occurred in seven patients over a mean follow-up period of 13 months. The total local recurrence rate was 16% (15 of 95 patients). The incidence of anastomotic recurrence was shown to be related only to the length of the proximal resection margin and not related to tumor differentiation or lymph node metastases. A proximal resection margin of less than 5 cm measured at operation had a 20% risk of developing an anastomotic recurrence, and a margin of between 5 to 10 cm had an 8% risk. Mediastinal recurrences that encroached on the intrathoracic stomach were found to be related more to the extent of lateral spread of the primary tumor in the mediastinum than to the length of the resection margins. Postoperative radiotherapy in patients with palliative resections decreased the incidence of local recurrences. To reduce the incidence and consequences of local recurrence after esophagectomy, it is suggested that in patients with tumors in the upper thorax, a more complete esophagectomy is warranted, postoperative radiotherapy should be given to patients with short resection margins, and in patients with extensive mediastinal spread, use of the retrosternal route for reconstruction is preferred.