Immune checkpoint inhibitors (ICIs) change the prognosis of many cancer patients. With the increasing use of ICIs, immune-related adverse events are occurring, including acute kidney injury (AKI). This study aimed to assess the incidence of AKI during ICI treatment and its risk factors and impact on mortality. Patients treated with ICIs at the First Medical Center of the Chinese PLA General Hospital from January 1, 2014, to December 30, 2019, were consecutively enrolled, and risk factors affecting AKI development in patients treated with ICIs were analyzed using univariate and multivariate logistic regression. Medical record surveys and telephone inquiry were used for follow-up, and Kaplan-Meier survival analysis and Cox regression were used to analyze independent risk factors for death. Among 1615 patients, 114 (7.1%) had AKI. Multivariate logistic regression analysis showed that anemia, Alb < 30 g/L, antibiotic use, diuretic use, NSAID use and proton pump inhibitor use were independent risk factors for AKI development in patients treated with ICIs. Stage 2 or 3 AKI was an independent risk factor for nonrecovery of renal function after AKI onset. Multivariate Cox regression analysis showed that anemia, Alb < 30 g/L, AKI occurrence, and diuretic use were independent risk factors for death in patients treated with ICIs, while high baseline BMI, other tumor types, ACEI/ARB use, and chemotherapy use were protective factors for patient death. AKI occurs in 7.1% of patients treated with ICIs. Anemia, Alb < 30 g/L, and combined medication use are independent risk factors for AKI in patients treated with ICIs. Anemia, Alb < 30 g/L, AKI occurrence, and diuretic use were independent risk factors for death in patients treated with ICIs.