Objectives: To determine the frequency of acute kidney injury (AKI) among patientsadmitted to surgical intensive care unit (ICU) for variant indications and todetermine the predictability of at admission AKI biomarkers levels for the possibilityof AKI development. Patients & Methods: The study included 168 patients with meanage of 53±6.7 years; 97 postoperative patients, 55 trauma patients and 16 patientshad other causes. Patients’ data were collected and disease severity was evaluatedusing the Acute Physiology and Chronic Health Evaluation (APACHE II) and thesimplified Therapeutic Intervention Scoring System (TISS-28). Development of AKIwithin the first 48 hours after ICU admission was defined according to the AcuteKidney Injury Network (AKIN) criteria using serum creatinine (sCr). Blood sampleswere obtained for ELISA estimation of at admission sCr and serum Cystatin C (CysC)and plasma Neutrophil gelatinase-associated lipocalin (NGAL) levels. Another bloodsample was obtained at 48 hours of ICU admission for colorimetric estimation of sCrand then patients’ categorization. Results: Estimated sCr at 48-hr after admissiondefined 62 patients developed AKI (36.9%); 39 patients AKI stage-1 (23.2%) and 23patients AKI stage-2 (13.7%). At admission plasma NGAL levels were significantlyhigher in patients compared to controls, however, AKI-free patients showed nonsignificantlyhigher plasma NGAL levels compared to controls. Patients developedAKI had significantly higher plasma NGAL levels compared to AKI-free patients withsignificantly higher levels in patients developed AKI-2 compared to those developedAKI-1. At admission serum CysC levels were significantly higher in patientscompared to controls and in patients developed AKI-2 compared to AKI-free andAKI-1 patients. Regression and Receiver operating characteristic (ROC) analysis ofat admission clinical and laboratory data as predictors for development of AKI,defined at admission plasma NGAL and serum CysC, and TISS-28 injury severityscore as the significant specific predictors for possibility of development of AKI.Conclusion: Patients admitted to surgical ICU had a risk of 36.9% for AKIdevelopment and combined high TISS-28 severity score and high at admission plasmaNGAL levels could early predict the possibility of AKI development with significantlyhigh specificity.