Tazobactam/piperacillin is a first-line treatment option for hospital-acquired pneumonia; however, drug-induced liver injury (DILI) is relatively frequently observed with tazobactam/piperacillin in clinical practice. This study aimed to verify the usefulness of available patient data for predicting DILI prior to tazobactam/piperacillin administration. Tazobactam/piperacillin-treated patients were retrospectively selected and divided into patients with and without DILI. Comparative analysis was performed regarding age, gender, dose, duration of treatment, clinical laboratory values prior to treatment initiation, and the types of organ-specific infections in both groups. Multiple logistic regression analyses indicated that elevated C-reactive protein (odds ratio (OR), 1.284; 95% confidence interval (CI), 1.172 - 1.406; p < 0.001) and high hemoglobin (OR, 1.697; 95% CI, 1.259 - 2.286; p < 0.001) levels prior to the administration of tazobactam/piperacillin were risk factors for DILI in males who received a 4.5-g dose. A predictive model for DILI risk was constructed by combining these test values and analyzed using receiver operating characteristic curves, obtaining 0.910 for the model construction set and 0.845 for the validation set. The development of DILI was predicted with good accuracy in males who received a 4.5-g dose with elevated C-reactive protein and hemoglobin.