Prophylactic systematic lymph node dissection was carried out in 538 patients with squamous cell carcinoma of the thoracic esophagus, with thoraco-abdominal (TA) or two-field dissection and collo-thorac-oabdominal (CTA) or three-field dissection being performed in 290 and 248 cases, respectively. The long-term results were compared between the TA and CTA dissection groups. The results after CTA dissection were significantly better than those after TA dissection in patients with both positive and negative nodes and in stage III – IV patients. In addition, overall survival was significantly better (excluding mucosal cancer). The 5-year overall survival rates after CTA and TA dissections were 52.2% and 37.1%, respectively, while the 5-year survival rate for all resected patients was 42.3%. Three-field (CTA) dissection is more extensive than two-field (TA) dissection and was proven to be significantly more effective in improving the survival of esophageal cancer patients while having an acceptable operative mortality and morbidity.