Introduction: Acute obstructive renal failure (AORF) in adults is a severe urological condition caused by obstruction in the urinary tract, leading to impaired renal function. Understanding this condition is crucial for improving patient management. Objectives: General Objective: To study the epidemiological, etiological, and diagnostic aspects of cases of acute obstructive renal failure (AORF) at CNHU-HKM. Specific Objectives: To describe the epidemiological aspects of AORF at CNHU-HKM, to identify the etiological aspects (causes) and to identify the therapeutic and evolutionary aspects. Patients and Methods: This retrospective and descriptive study was conducted on adult patients treated for acute obstructive renal failure at the urology and andrology departments and emergency services of CNHU-HKM from January 1, 2019, to January 1, 2023. Included patients had a sudden increase in serum creatinine exceeding 14 mg/L upon admission, associated with urinary tract obstruction confirmed by imaging. Data were collected and analyzed using Kobocollect and Excel software. Results: 151 cases of acute obstructive renal failure were recorded out of 1720 hospitalizations during this period, representing 8.7%. The mean age of patients was 63 years, with a predominance of males (84.1%), giving a male-to-female ratio of 5.2. The majority of patients were civil servants (48%), followed by artisans and merchants (14% each). Main admission symptoms included lower urinary tract symptoms (55.6%), renal colic (13.6%), and hematuria (10.6%). The most common medical history included hypertension (39.1%) and diabetes (14%). Metabolic disorders observed included hypercreatininemia ranging from 15 to 306 mg/L (mean 64.1 mg/L), hyperuricemia from 0.50 to 1.89 g/L (mean 1.28 g/L); hyperkalemia in 17% of patients versus hypokalemia in 8% (extremes: 2.9 to 8.2 mEq/L); hypernatremia in 0.8% versus hyponatremia in 33.8% (extremes: 115-168 mEq/L); hyperchloremia in 7% and hypochloremia in 17% (extremes: 41-190 mEq/L). The main etiologies were tumors (prostate 59.6%, bladder 9.3%), followed by urinary stones (13.6%). Non-urological causes included cervical tumors in women (3.3%) and colonic tumors (1.3%). The obstruction was mainly subvesical (61%). The most common urinary drainage was urethral catheterization (40%), followed by JJ stent placement (20%). The predominant etiological treatment was transurethral resection of the prostate (15%), with prostatic drilling (14%). Hemodialysis was performed in 6% of patients. Serum creatinine normalized in an average of 10.03 days in 40.3% of patients, serum potassium in 6 days in 75.7%, and serum sodium in 9 days in 84.6%. Progression to chronic obstructive renal failure was observed in 7.9% of patients. Conclusion: Acute obstructive renal failure is a frequent urological emergency at CNHU-HKM in Cotonou. The main causes are prostatic tumors followed by urinary stones. Rapid and appropriate management is essential to prevent progression to chronic renal failure.