Introduction: Acute kidney injury has a high morbidity and mortality outcome so need highly sensitive marker to assess the degree of tubular affection for early detection and management to prevent further complication. Methods: We investigated the ability of a furosemide stress test (FST) (one-time dose of 1.0 or1.5 mg/kg depending on prior furosemide-exposure) to predict the development of AKIN Stage-III in critically ill subjects with early AKI which considered group I. and group II who received standard management for AKI. Result: We studied 80 subjects; 40 consecutive patients in group I and 40 consecutive patients in group II; 25 (37.5%) and (50%) met the primary endpoint of progression to AKIN-III in group I, II consequently. patients with progressive AKI had significantly lower urine output following FST in the first 6 hours (p