PURPOSE: The risk factors and clinical characteristics of ICI-induced immune-mediated hepatotoxicity (IMH) are not fully understood. Thus, the present study sought to clarify the clinical features of IMH. METHODS: All patients treated with ICIs between September 2014 and April 2019 at our institution were included. Clinical data were retrospectively collected from medical records. The frequency of grade ≥ 2 liver damage, clinical characteristics, and risk factors for developing IMH were examined. RESULTS: Overall, 250 patients (median age 71 years; range 30-87 years; 202 males and 48 females) were included in the analyses. Forty-five patients had elevated transaminase levels (> threefold the upper limit of normal). Of these, 21 were considered to have IMH. The remaining 24 patients had other causes of elevated transaminase levels. Steroids were administered to 13/21 patients with IMH. Although all patients exhibited improvement, IMH was not associated with the anticancer efficacy of the ICIs or OS. A multivariable analysis revealed that IMH was significantly associated with malignant melanoma (odds ratio [OR] 11.6; 95% confidence interval [CI] 3.5-38.0; P = 0.0002) and ipilimumab-nivolumab combination therapy (OR 61.2; 95% CI 7.9-1275.3; P < 0.0001). CONCLUSION: Immune-mediated hepatotoxicity occurred in 9.5% of patients treated with ICIs. Appropriate therapeutic interventions are important to avoid affecting the patient's prognosis, and accurate diagnosis of IMH is essential for this purpose. The frequency of IMH varied according to the type of cancer and the drug used, and was significantly higher in patients with malignant melanoma and in patients given ipilimumab-nivolumab combination therapy.