Background: CheckMate 577 trial demonstrated efficacy of adjuvant nivolumab (Ad-Nivo) therapy in locally advanced esophageal cancer patients (pts) who underwent surgery after neoadjuvant chemoradiotherapy and did not achieve pathologic complete response. In Japan, neoadjuvant docetaxel plus cisplatin, 5-FU (NeoDCF) therapy is the standard care for locally advanced resectable esophageal squamous cell carcinoma (ESCC) based on the results of the JCOG1109 study. The efficacy and safety of Ad-Nivo therapy after NeoDCF therapy were unknown, so guidelines recommendations have not been determined. Methods: The subjects of this retrospective study were pts with histologically confirmed resectable locally advanced ESCC who received Ad-Nivo (480mg/body, every 4 weeks for 12 times) after NeoDCF in our hospital from Jan 2022 to Sep 2022. We evaluated safety as adverse events during treatments and clinical outcomes. Results: Twenty pts were selected in this study. Characteristics were median age (range) 65 (51–75) years, male/female 70/30%, PS 0/1 85/15%, Ce/Ut/Mt/Lt 5/15/50/30%, clinical stage II/III/IVA/IVB (supraclavicular lymph node) 10/70/0/20%, pathological stage IIB/IIIA/IIIB/IVA/IVB 30/5/40/10/15%. The pathological response according to Japanese Classification of Esophageal Cancer was Grade 0/1a/1b/2/3 5/20/20/40/15%. Median time (range) from surgery to Ad-Nivo was 9 weeks (4-20 weeks). The adverse events included fatigue (30%), increase AST (30%), increase ALT (15%), pruritus (15%), hyperthyroidism (15%), diarrhea (10%), decreased appetite (10%), and pneumonitis (10%). Grade >3 adverse events were not observed. Recurrence was observed in three pts (15%), which site was regional lymph node (2 pts of pathological stage III and IVB) and anastomosis (1pt of pathological stage IVA). Three pts with recurrence received definitive chemoradiotherapy, and still continue the treatment. Conclusions: The short-term toxicity of Ad-Nivo after NeoDCF was well-tolerated and acceptable.