Introduction: Acute kidney injury (AKI) is a commonly encountered problem in the paediatric intensive care unit (PICU). There are limited reports on paediatric AKI from the Indian subcontinent. Objective: To determine the incidence, aetiology and outcome in paediatric AKI using Acute Kidney Injury Network (AKIN) criteria. Method: This prospective observational study was conducted in the PICU of a teaching hospital in Western Maharashtra, India, from July 2016 to June 2017 on patients aged 1 month to 17 years. Results: The incidence of AKI was 18.8% (80/426). The mean age was 70 ± 60 months. Most (66.3%) cases had stage I AKI and 54% developed AKI within 72 hours. Sepsis (35%), pneumonia (25%) and tropical febrile illnesses (18.7%) were the common aetiologies. Complete recovery (CR) was seen in 79% and partial recovery (PR) in 21%. CR was highest in stage I (91%) as compared to stages II and III (p=0.005). Mortality was 22% (18/80). Mortality significantly increased with the stage of AKI (p=0.003). Mechanical ventilation, inotrope support, shock and the stage of AKI had a significant association with mortality on bivariate analysis. Mechanical ventilation was found to be a significant independent predictor of mortality (p= 0.011). Renal replacement therapy was needed in 6 (8%) cases. Conclusions: About one-fifth of children admitted to ICU developed AKI and most experienced mild transient AKI. Moderate to severe AKI carried high mortality suggesting a dose-response effect. Infections remain the commonest cause and mechanical ventilation was an independent predictor of mortality.