Background: Postoperative Acute Kidney Injury (PO-AKI) poses a substantial risk to patients, impacting their prognosis. Objectives: Assessing the incidence of AKI within the first 72 hours after surgery according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria and to assess preoperative, intraoperative and postoperative risk factors for the development of PO-AKI. Patients and Methods: We conducted an analytical cross sectional study in patients undergoing major surgery more than 2-hour duration. The recruited patients were divided into two groups, one group that developed PO-AKI and the other group that didn't develop PO-AKI. The primary endpoint was the occurrence of PO-AKI within 72 hours of surgery defined by the KDIGO criteria. Secondary endpoints included PO-AKI severity and duration, use of renal replacement therapy (RRT), mortality, Intensive Care Unit (ICU) and Hospital length of stay. Results: This study included 498 patients. 101 of 498 (20.28%) patients developed PO-AKI within 72 hours after surgery (primary endpoint; stage 1: 40 (39.6%), stage 2: 39 (38.6%), stage 3: 22 (21.8%). Patients with PO-AKI had significantly longer ICU (mean 3.15 days vs. 0.48 days) as well as hospital length of stays (mean 9.17 days vs. 5.15 days), higher mortality rates (5.9% vs. 0.8% compared to non-PO-AKI patients. Multivariate analysis revealed that (BMI >28.39, hypertension, surgery duration>3.19 h, intraoperative hypotension, preoperative NSAID and intraoperative nephrotoxic drugs were significant risk factor for developing postoperative AKI. Conclusion: One in five patients were at risk for the development of PO-AKI. Intraoperative hypotension, surgery duration and preoperative NSAIDs were risk factors for PO-AKI. Patients with PO-AKI had considerably higher mortality rates, ICU admissions, and hospital stays.