BackgroundThe time interval between neoadjuvant immunotherapy and surgery is 6 weeks for esophageal squamous cell carcinoma (ESCC), but whether delayed surgery affects prognosis remains unclear.MethodsClinical data of locally advanced ESCC who underwent neoadjuvant immunotherapy followed by esophagectomy from November 2019 to December 2022 were collected. The surgery outcomes and prognosis were compared between short-interval (time to surgery ≤ 6 weeks) and long-interval groups (time to surgery > 6 weeks).Results152 patients were enrolled totally, with a ratio of 91:61 between short-interval and long-interval groups. The rate of pathological complete response in the short-interval and long-interval groups were 34.1% and 24.6% (P = 0.257). Delayed surgery did not have a significantly impact on the number of lymph node dissections (P = 0.133), operative duration (P = 0.689), blood loss (P = 0.837), hospitalization duration (P = 0.293), chest drainage duration (P = 0.886) and postoperative complications (P > 0.050). The 3-year Overall survival (OS) rates were 85.10% in the short-interval group, and 82.07% in the long-interval group (P = 0.435). The 3-year disease-free survival (DFS) rates were 83.41% and 70.86% in the two groups (P = 0.037). Subgroup analysis revealed that patients with a favorable response to immunotherapy (tumor regression grade 0) exhibited inferior 3-year OS (long-interval vs. short-interval: 51.85% vs. 91.08%, P = 0.035) and DFS (long-interval vs. short-interval: 47.40% vs. 91.08%, P = 0.014) in the long-interval group.ConclusionsDelayed surgery after neoadjuvant immunotherapy does not further improve pathological response; instead, it resulted in a poorer DFS. Especially for patients with a favorable response to immunotherapy, delayed surgery increases the risk of mortality and recurrence.