Objective: to know the epidemiology of Acute Kidney Injury (AKI) in the pediatric population at Hospital Universitario del Valle (HUV), a tertiary University Hospital in Cali, Colombia. Methods: We obtained a series of cases through daily surveillance for a seven-month period (June 1 to December 31, 2009) in patients older than 30 days and under 18 years at HUV. We excluded patients with previous diagnosis of chronic renal failure. The new pRIFLE scale was used to define AKI. Results: 27 patients were detected, with mean age of 36 months. Incidence of AKI was 0.38% from pediatric admissions and 6.2% from the pediatric intensive care unit (pICU) admissions. The pRIFLE scale at study entrance was: Risk: 2 patients, Injury: 8, Failure: 17. Etiology of AKI was: pre-renal in 89%, primary renal disease in 3.7%, and post-renal in 7.4%. There was an association of AKI with sepsis in 66.7% and 48.2% progressed to septic shock. Six patients required renal replacement therapy, all required peritoneal dialysis. The AKI was multi-factorial in 59.3% and associated with systemic multi-organ failure in 59.3%. At study entry, 63% patients were in pICU. The average hospital stay was 21.3 ± 9.2 days. Six children died, 16 resolved AKI, and nine were left with renal sequelae. Conclusions: We recommended pRIFLE scale for early diagnosis of AKI in all pediatric services. Education in pRIFLE scale, prevention of AKI, and early management of sepsis and hypovolemia is recommended.