Background: Nivolumab, an immune-checkpoint inhibitor for unresectable or recurrent esophageal cancer is used as second-line treatment. On the other hand, the relationship between indicators of cancer immunity (GPS, NLR, PLR), indicators of nutritional status (PNI, BMI), and prognosis of patients treated with nivolumab is unclear. Methods: We investigated the prognostic factors of nivolumab for unresectable or recurrent esophageal cancer. The subjects were 62 patients who received nivolumab as a second-line or later treatment for unresectable or recurrent esophageal cancer before January 2021. Of these 13 patients had previously been treated with taxan. We used GPS (Glasgow prognostic score), NLR (Neutrophil-Lymphocyte Ratio: cutoff value is 3.5), PLR (Platelet-Lymphocyte Ratio: cutoff value is 200), PNI (Prognostic nutrition index: cutoff value is 40), BMI (Body mass index: cutoff value is 18.5 for under 70 years old, and 20 for over 70 years old defined by Asian GLIM standard) as prognostic indicators. We examined the association between age, gender, PS, GPS, NLR, PLR, PNI, BMI and prognosis in patients treated with nivolumab. And we also examined the relationship between the history of taxan administration, the presence of adverse events and the prognosis. Results: Of the 62 cases, 48 cases were male and 14 cases were female. The median age was 70 years. Median OS was 359 days, and median PFS was 97 days. OS in patients with no prior taxan treatment group was significantly longer (P<0.05). AE appeared in 49 cases (79%), and irAE appeared in 22 cases (35.5%). OS in patients with irAE was significantly longer (P<0.01). PS (0/1/2) was 27 cases/33 cases/2 cases, and GPS (0 point/1 point/2 point) was 41 cases/11 cases/10 cases. NLR high was 35 cases, and NLR low was 27 cases. PLR high was 31 cases and PLR low was 31 cases. PNI high was 46 cases and PNI low was 16 cases. BMI normal or high was 27 cases and BMI low was 35 cases. In univariate analysis of OS, GPS (P<0.001), NLR (P<0.01), PS (P<0.05), PNI (P<0.001) showed a significant difference in survival, and in multivariate analysis, PS (p<0.05) and PNI (P<0.05) were significant prognostic factors. Conclusions: PS and PNI were good prognostic factors with nivolumab after second or later treatment for unresectable or recurrent esophageal cancer.