Introduction: Acute kidney injury is a syndrome characterized by the rapid loss of the kidney'srnexcretory function and is typically diagnosed by -the accumulation of end products of nitrogenrnmetabolism (urea and creatinine) or decreased urine output, or both. In critically ill patientsrnAcute Kidney Injury (AKI)occurs frequently and it allied with great rates of morbidity andrnmortality.rnObjective: This study aims to assess the prevalence, risk factors and outcome of acute kidneyrninjury in patients admitted in the intensive care unit of Saint Paul's Hospital Millennium MedicalrnCollege from January 2017 to December 2019.rnMethods: The study design was a facility-based retrospective; the cross-sectional study wasrnconducted. Medical records of 108 were revised. Data collection checklist was developed and therndata were extracted from the patients' medical records. Data entry and analysis were conduct byrnusing the Epi-Data-4.2 and Statistical Package for the Social Sciences (SPSS) software versionrn25.0 respectively. The logistic regression model was used for analysis.rnResult: AKI in critically ill patients covered 16.1% with a mean age of 34 Â± 15 age distribution andrnfemale predominance (66.7%). Being female and Anemia were the leading risk factors torndevelop AKI, 72 (66.7%)and 56 (51.9%) respectively. Sepsis was more likely associated tornkill the patients with AKI. Most 81 (75%) AKI critically ill patients were initiated renalrnreplacement therapy. Stage three AKI were account for 66(61.1%). Length of hospital stayrnranged from 1 day to 52 days with a mean stay of 10.7 days. Critically ill patients with AKIrn(48.1%) had died in the study period.rnConclusion: AKI is the most common cause for critically ill patient's morbidity I too observedrnthe higher prevalence of AKI in critically ill patients with younger age groups and femalernpredominance. The mortality rate of AKI in critically ill patients was near to half of allrnrespondents during the study period.