Patients with deeply invading (T3-T4) oesophageal cancers usually receive chemoradiotherapy with or without surgery. However, the prognostic significance of pre-therapy and post-therapy lymph node (LN) status remains unclear. We studied 195 patients who received chemoradiotherapy for deeply invading oesophageal cancers (T3-4, N0-1, M0). Of these, 105 patients underwent surgery while 90 were treated by chemoradiotherapy alone. Of the 105 surgically treated patients, overall survival was significantly better in cN0 patients than in cN1 (3-year survival rate, 65.3 vs. 25.8%, P=0.0014). This difference was similarly observed in 90 patients who received chemoradiotherapy alone. Patient survival differed significantly among patients with no positive LN, 1 positive LN and 2-4 positive LN (3-year survival rate, 57.1 vs. 40.5 vs. 17.6%, P<0.0001). However, there was no significant difference in survival between patients with 2-4 positive LN and > or =5 positive LN. Multivariate analysis identified pre-therapy LN status and the number of involved LNs as the most important independent prognostic factors prior to histopathological tumour regression. In conclusion, pre-therapy LN status and the number of post-therapy involved LNs equally affect survival of patients who receive neo-adjuvant chemoradiotherapy. Control of systemic metastasis is required, based on pre- and post-therapy LN status.