Background <p>Postoperative length of stay (LOS) after esophagectomy varies substantially and is influenced by multiple perioperative factors. Whether prolonged LOS is associated with long-term oncologic outcomes remains unclear.</p> Methods <p>This retrospective single-center cohort study included 84 patients who underwent esophagectomy between 2017 and 2018. Receiver operating characteristic (ROC) curve analysis was used to define prolonged LOS. Overall survival (OS) and disease-free survival (DFS) were analyzed using Kaplan–Meier methods. Multivariable Cox regression models were constructed with a limited set of clinically relevant covariates to evaluate the association between prolonged LOS and long-term outcomes.</p> Results <p>An LOS of ≥ 17 days was identified as the optimal cutoff to define prolonged LOS. Patients with prolonged LOS experienced significantly higher postoperative complication rates and worse 5-year OS and DFS compared with those with normal LOS. After adjustment for age, ASA classification, pathological stage, and postoperative complication severity, prolonged LOS remained significantly associated with reduced OS and DFS. Major postoperative complications, particularly anastomotic fistula and pulmonary infection, were also associated with poorer long-term outcomes.</p> Conclusion <p>Prolonged LOS after esophagectomy is associated with adverse long-term survival outcomes and may serve as a clinically informative prognostic indicator reflecting perioperative vulnerability and delayed recovery. LOS should be interpreted as a surrogate marker of postoperative recovery, rather than a causal determinant of survival.</p>