Background: One of the most serious complications among cancer patients is Acute Kidney Injury (AKI). This study aimed to detect the AKI incidence in cancer patients, to discover which clinical factors could increase the risks of AKI, and to assess the effect of AKI on in-hospital mortality, length of stay. Methods: This prospective cohort study was conducted on 276 malignant patients (AKI: 40 cases and no AKI: 236 cases). Serum creatinine, blood urea, complete blood count, uric acid, Electrolyte'' potassium, sodium, calcium'', urine analysis with comment on RBCs cast, liver function test'' ALT, AST, Albumin and bilirubin'' were measured every three weeks, and urine albumin creatinine ratio was done before chemotherapy and after finishing treatment. Results: pre-existing comorbidities including hypertension (HTN), diabetes (DM), and coronary heart disease are significant predictors for increased risk of AKI in cancer patients. Patients with hyponatremia, hypokalemia and hyperuricemia shared a significantly higher risk of AKI (aOR = 2.95, 2.49, and 3.01). Cox regression analysis revealed that HTN and DM also increased the mortality risk when adjusting demographic and clinical features. The mean survival rate was significantly lower in group with AKI compared to group without AKI (16.331 versus 19.589). AKI stage II and III had longer median length of hospital stay compared to stage I. Conclusion: The in-hospital mortality was 5% in cancer patients with AKI. The severe AKI was associated with poor clinical outcome, long hospital stay and high daily costs. Pre-existing comorbidities and electrolyte disturbances are the predicting factors for AKI incidence.