Abstract: BACKGROUND:The advancement of neonatology over the past 20 years has allowed a greater number of ELBW infants to survive. However, these advancements have contributed to the increased incidence of acute kidney injury (AKI) seen in this population. Understanding the risk factors for AKI in this population of ELBW infants is imperative for the successful survival of these infants since the morbidity and mortality rates from this disease are increasing. OBJECTIVES:1) to determine the prevalence of AKI in ELBW (< 750 grams). 2) to compare the mortality rate of ELBW infants (< 750 grams) with and without AKI; and 3) to identify the associated risk factors of AKI in ELBW infants (< 750 grams). METHODS:A retrospective chart review of all infants with AKI as defined by AKIN criterias, admitted to the NICU between 1998 and 2008 was conducted. Case-controls were matched for BW, gestational age and date of birth, (SPSS v17.0 software, using Student’s t test, X2 test, and Mann-Whitney U test were used for statistical analysis. CONCLUSION:The prevalence rate of ELBW infants (< 750 grams) with AKI admitted at CHMCA NICU from 1998 to 2008 was 26% . The mortality rate of ELBW infants (< 750 grams) with AKI was 54% , compared to 20% in those ELBW infants who did not have AKI. The associated risk factors of AKI in the ELBW infants (< 750 grams) were as follows: presence of maternal placental abruption/bleeding, grade III or IV IVH, PDA, positive culture/s, NEC, use of steroid, nephrotoxic drugs, and longer use of the ventilator and TPN.