Although atezolizumab plus bevacizumab (Atezo/Bev) therapy has been used as the preferred first-line treatment for advanced hepatocellular carcinoma (HCC), up to 26% of patients do not achieve disease control, suggesting alternative treatments might be more beneficial for such patients. We investigated key predictors for refractoriness to Atezo/Bev therapy, particularly in the first-line setting. We retrospectively analyzed 302 patients with HCC who received Atezo/Bev therapy between October 2020 and September 2022 across nine hospitals in Japan. Refractoriness was defined as best overall response (BOR) of progressive disease or stable disease and a progression-free survival (PFS) of < 180days (RECIST v1.1). Clinical benefit was defined as BOR of partial/complete response or stable disease with PFS of ≥ 180days. Baseline characteristics and potential predictors, identified through literature review, were compared between these groups. Stratifications of overall survival (OS), and PFS were also assessed. Refractoriness was observed in 126 (41.7%) patients, while 154 (51.0%) achieved clinical benefit. Due to a significant association between the treatment line and refractory rate, the subsequent analysis focused on the first-line cohort (n = 214; 72 [33.6%] patients showed refractoriness). Among 13 potential predictors, the CRP and AFP in immunotherapy (CRAFITY) score had the best predictive performance, with refractory rates of 24.6%, 44.6%, and 57.9% in CRAFITY-0, 1, and 2 patients, respectively (p < 0.001). OS and PFS were also well-stratified by this scoring system. Approximately one-third of patients were refractory to first-line Atezo/Bev therapy. The CRAFITY score demonstrated superior performance in predicting refractoriness.