Objectives: This study aimed to identify the incidence and risk factors for contrast-associated acute kidney injury nephropathy (CA-AKI) in patients undergoing contrast-enhanced computed tomography (CCT) in the emergency department. Materials and Methods: In this retrospective single-center study, patients aged 18 and older who visited the emergency department and underwent CCT between January and February 2022 were included. The Mehran score, calculated from patient data, was used to assess risk. CA-AKI development was determined by measuring serum creatinine (SCr) levels 48–72 h post-contrast administration. Results: The study included 532 patients, with a mean age of 57 ± 19 years; 53.2% were male. CA-AKI developed in 16% of cases, 5.82% required hemodialysis, and 7.9% died. The Mehran score was the only significant predictor of CA-AKI development. Patients with a Mehran score of 16 or higher had a 161-fold increased risk of developing CA-AKI compared to those with a score of 5 or lower. The model achieved a 91.3% correct classification rate. Logistic regression analysis showed that CA-AKI significantly increased mortality risk by 15.7 times. Conclusion: The Mehran score, originally developed for predicting CA-AKI risk post-coronary intervention, is also effective for predicting CA-AKI risk after CCT. While CA-AKI is a significant factor affecting mortality, it is not the sole cause of death (Nagelkerke R2 value 0.310).