Objectives: This study aimed to assess the current incidence and risk factors for polymyxin B-associated acute kidney injury (AKI) in Chinese hospitals for a more effective clinical use for polymyxin B. Methods: This multicenter, retrospective cohort study included patients from 14 Chinese teaching hospitals who received polymyxin B therapy. Univariate and multivariate logistic regression models were used to determine the factors associated with polymyxin B-associated incident AKI. Furthermore, a multivariate logistic regression model was used to identify the independent risk factors for AKI. Results: A total of 251 patients were included in the analysis. The overall incidence of AKI was 33.5%. A multivariate logistic regression model identified the loading dose (hazard ratio (HR), 1.84; 95% confidence interval (CI), 1.01-3.38; P = 0.0491) and the use of two or more nephrotoxic drugs (HR, 3.56; 95% CI, 1.55-8.18; P = 0.0029) as independent risk factors for the occurrence of AKI. Meanwhile, the estimated glomerular filtration rate had a protective effect (HR, 0.99; 95% CI, 0.98-0.99; P = 0.0 0 06) on the occurrence of AKI. The daily dose, cumulative dose, and treatment duration of polymyxin B did not affect the occurrence of AKI.Conclusions: The use of polymyxin B loading doses and the combined use of multiple nephrotoxic drugs are independent risk factors for polymyxin B-associated AKI. The severity of AKI may be higher in patients with elevated baseline creatinine levels.(c) 2022 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)