Aim: To study the clinical features and broad spectrum of etiologies in patients with acute renal injury in a specialized hospital. Material and methods: This prospective observational study was conducted in the Department of Medicine, focusing on patients diagnosed with acute renal injury (ARI). The study aimed to examine the clinical characteristics and range of causes of ARI in a cohort of 100 patients.A total of 100 patients diagnosed with acute renal injury were included in the study. Acute renal injury was defined as an abrupt decrease in kidney function, characterized by a significant increase in serum creatinine levels (≥ 0.3 mg/dL within 48 hours or a 50% increase from baseline) and/or a decrease in urine output (oliguria: < 0.5 mL/kg/h for more than six hours). Results: A total of 75% of the patients experienced recovery of renal function, with the highest recovery rates observed in the prerenal group (28 out of 35), likely due to the reversible nature of conditions like dehydration or hypotension when promptly treated. However, 15% of the patients progressed to chronic kidney disease (CKD), with the intrarenal group showing the highest progression rate (8 out of 45), underscoring the long-term impact of intrinsic renal damage. The mortality rate in the study was 10%, with intrarenal causes being associated with the highest mortality (5 out of 45), reflecting the severity of conditions like acute tubular necrosis and the challenges in managing these patients. Postrenal causes had a slightly higher mortality rate (3 out of 20) compared to prerenal causes, likely due to complications related to delayed diagnosis or intervention in obstructive uropathy. Conclusion: This study highlights the significant impact of acute renal injury (ARI) on middle-aged and older adults, with a higher prevalence among males. The results reveal that intrarenal causes are the most common, followed by prerenal and postrenal causes. The elevated serum creatinine and BUN levels, particularly in the intrarenal group, underscore the severity of renal impairment associated with intrinsic renal damage. Comorbid conditions, such as hypertension and diabetes, were prevalent, further complicating the management of ARI.