The aim of this study was to investigate the relationship between serum procalcitonin (PCT) levels after esophagectomy and infectious complications and long-term prognosis. A total of 105 patients who underwent esophagectomy between 2012 and 2019 were stratified into two groups: PCT-High group of ≥1 ng/mL and PCT-Low group of <1 ng/mL. The clinical outcomes and prognostic factors were compared between the two groups 2 postoperative days (POD), 4 POD, and 7 POD after esophagectomy. As the postoperative days passed, the association between PCT and infectious complications became stronger, and the positive predictive value was 100% at 7 POD. At 2 POD, there was no significant association between PCT elevation and infectious complications. Patients in the PCT-Low group had significantly worse overall survival (OS) and recurrence-free survival (RFS) than those in the PCT-High group at 2 POD (p = 0.026 and p = 0.011, respectively). In multivariate analysis, advanced pathological stage (hazard ratio (HR), 5.348; 95% confidence interval (CI), 2.299–12.500; p < 0.001) and PCT-Low group at 2 POD (HR, 3.673; 95% CI, 1.116–12.092; p = 0.032) were also independent predictors of worse OS. PCT in the early postoperative period after esophagectomy could be a good predictor of prognosis.