This study aimed to investigate the significance of neutrophil-to-lymphocyte ratio (NLR) as a prognostic predictor by reporting 21 patients with unresectable hepatocellular carcinoma (HCC) treated with atezolizumab plus bevacizumab (Atezo/Bev) as the first line of treatment. The optimal cut-off value of NLR was 2.25 with Atezo/Bev, and patients with NLR of ≥2.25 had a shorter progression free survival (PFS) (199 vs. 393 days, p=0.009) compared to patients with NLR of <2.25. NLR was positively correlated with C-reactive protein (r=0.525, p=0.016). The high NLR group demonstrated a shorter PFS than the low NLR group. NLR may be a useful predictive biomarker of the first-line Atezo/Bev treatment for unresectable HCC.