Patients with locally advanced and potentially curable esophageal cancer (EC) should receive trimodality treatment, which involves neoadjuvant concurrent chemoradiotherapy (nCRT) followed by esophagectomy. The maximum standard uptake value (SUVmax) in SUV of 18FDG-PET/CT have been reported to be useful in predicting the prognosis of EC patients treated with nCRT and subsequent esophagectomy. We aimed to determine the pathological response in patients with EC after trimodality therapy and to investigate the prognostic factors associated with SUVmax. This was a retrospective study of patients with locally advanced esophageal squamous cell carcinoma who received nCRT followed by esophagectomy between January 2011 and December 2018 at the Tri-Service General Hospital in Taipei, Taiwan. Survival analysis was performed using the Kaplan–Meier method and the Cox proportional hazards model. Univariate and multivariate analyses were used to determine the independent prognostic factors. A total of 79 patients with esophageal cancer underwent esophagectomy, and 50 of them were enrolled in the study. Among the 50 patients enrolled, 18 had a pCR. A post-nCRT maximum standard uptake value (SUVmax) ≥ 3 was a poor prognostic factor associated with OS (hazard ratio [HR]: 3.665, P = 0.013) and PFS (HR: 3.417, P = 0.011). Poor prognosis was found in patients with pCR and a post-nCRT SUVmax ≥3 as compared with those with pathological partial response and a post-nCRT SUVmax <3. SUVmax ≥3 is a poor prognostic factor in ESCC after trimodality treatment, even in patients with pCR.