Introduction: An acute and potentially reversible decline in renal function, which impairs the kidneys ability to eliminate nitrogenous waste products and maintain fluid and electrolyte balance, is the hallmark of acute kidney injury. Depending on the definitions employed, the population being investigated, and the clinical settings, there is a significant difference in the epidemiological statistics of acute kidney injury. Methods: The Institutional Ethics Committee approved this cross-sectional observational study in a semi-urban tertiary-care teaching hospital. All patients with RIFLE-defined acute renal failure were included. Patients under 18 were excluded. The investigation included a detailed history, physical exam, and systemic assessment. Throughout hospitalisation, we categorised patients by RIFLE class (R, I, or F). GFR or urine output determined RIFLE class. Using serum creatinine and urine output, we categorised patients. Results: Amongst the 100 cases of AKI, 46 cases (46%) were females while 54 cases (54%) were males.. The mean age at presentation was 55.22 ± 14.91 years. Sepsis was found to be the major cause of AKI. Out of 100 patients in our study, 64 (64%) cases were attributed to sepsis. Mortality rate seen in this study was 40% (n=40). Conclusion: Acute Kidney Injury is a common complication in ICU patients. Early detection and care reduce AKI-related and all-cause death in critically sick patients.