We retrospectively investigated the association between tumor infiltrating lymphocytes (TILs) of initial pathology and prognosis in patients treated with nivolumab. Twenty-eight patients with human papilloma virus and Epstein-Barr virus unrelated head and neck squamous cell carcinoma were enrolled....In univariate analysis...PD-L1 was also significant prognostic factor both in progression-free survival and overall survival (p = 0.01, 0.01, respectively)....In the combined analysis of stromal CD8+TIL and PD-L1, PD-L1 positive with high stromal CD8+TIL subgroups had a better prognosis than PD-L1 negative with low stromal CD8+TIL subgroups in progression-free survival (p = 0.006).