Background: Acute kidney injury is an independent risk factor for morbidity and mortality in critically ill neonates. Despite the high magnitude of preterm neonates and their being at a high risk for acute kidney injury, there is a paucity of information regarding the magnitude and associated factors of acute kidney injury among preterm neonates in the study area. Objective: The aim of this study was to assess magnitude and associated factors of acute kidney injury among preterm neonates admitted to public hospitals in Bahir Dar city, Ethiopia, 2022. Method and materials: An institutional-based cross-sectional study was conducted among 423 preterm neonates admitted to public hospitals in Bahir Dar city from May 20 to June 20, 2022. Epi Data Version 4.6.0.2 was used for data entry and cleaning. Statistical analysis was done by Statistical Product and Service Solutions version 26. Descriptive and inferential statistics were employed. A binary logistic regression analysis was done to identify factors associated with acute kidney injury. Variables with a p-value <0.05 were considered as statistically significant in the multiple binary logistic regression analysis. Model fitness was checked through Hosmer-Lemeshow goodness of fit test. Finally, the result was presented via a table, figures, and text. Result: Out of 423 eligible, 416 neonatal charts were reviewed with a response rate of 98.3%. The prevalence of acute kidney injury was 18.27 %( 95%CI = 15-22). Very low birth weight (AOR = 3.26; 95%CI = 1.18-9.05), perinatal asphyxia (AOR = 2.84; 95%CI = 1.55-5.19), dehydration (AOR = 2.30; 95%CI = 1.29-4.09), chest compression (AOR = 3.79; 95%CI = 1.97-7.13), and pregnancy-induced hypertension (AOR = 2.17; 95%CI = 1.20-3.93) were factors significantly associated with the development acute kidney injury. Conclusion: Acute kidney injury was high. The odds of acute kidney injury were high among neonates who were very low birth weighted, perinataly asphyxiated, dehydrated, recipients of chest compression, and born from pregnancy-induced hypertensive mothers. Therefore, clinicians have to be extremely cautious and actively monitor renal function in this neonatal population in order to detect and treat acute kidney injury as early as possible. Key words: Acute kidney injury, Preterm, Magnitude, Bahir Dar, Ethiopia