Whether the TNM staging system is applicable after neoadjuvant chemoradiation in esophageal cancer is controversial. The aim of this study was to evaluate the prognostic value of histopathological regression of the primary tumor in postchemoradiated patients. The pretherapeutic and pathological ypTNM stages of patients who have had neoadjuvant chemoradiation followed by esophagectomy were analyzed. The percentage of residual viable cells of the primary tumor (ypV) and other clinicopathological factors were tested for their prognostic value. Of 175 recruited patients, 55 (31.4%) achieved pathological complete response. The median survival of these 55 patients was significantly longer than those with other disease stages (124.8 vs 21.1 months) (P < .001). Gender, ypT, ypN, ypTNM, and ypV stage were significant prognostic factors in univariate analysis. In patients without nodal metastases, the median survival in patients with residual viable cells in the primary tumor (ypV+) was 24.6 months, compared with that of 124.8 months in those with no viable cells (ypV0) (P = .043). In those who had nodal metastases, the median survival of patients with ypV0 and ypV+ were 21.2 months and 17.4 months respectively (P = .37). Cox regression analysis showed that male gender, high percentage of residual viable cells (ypV), and positive nodal status (ypN1) were independent predictors of poor prognosis. In patients who underwent neoadjuvant chemoradiation therapy, histopathological regression of the primary tumor indicated by percentage of residual viable cells is an important prognostic factor in addition to nodal status and gender.