<p>Acute kidney injury (AKI) in paediatrics is a significant global health concern affecting up to one-third of hospitalised children worldwide. Increasing evidence demonstrates that childhood AKI is associated with substantial healthcare resource utilisation and adverse long-term health outcomes, including prolonged hospitalisation, higher healthcare costs, and chronic kidney disease. Consequently, AKI imposes a considerable socioeconomic and health burden. Despite this, recognition, documentation, and post-discharge follow-up of AKI survivors remain suboptimal, further compounding its impact. Efforts to characterise the epidemiology, risk factors, and long-term outcomes of paediatric AKI have been challenging due to methodological constraints, including small sample sizes, short follow-up durations, and a predominance of single-centre and selective cohort studies. Health systems research (HSR) offers a promising approach to address these gaps by leveraging large repositories of routinely collected health administrative data for various purposes to enable population-level analyses with extended longitudinal follow-up across diverse healthcare settings. However, HSR methodologies are not without limitations, as administrative data often lack granularity, can be incomplete, and may be subject to misclassification and selection biases, underscoring the importance of validating coding algorithms to ensure their reliability. In this review, we aim to summarise health systems evidence on the epidemiology of paediatric AKI, its implications on healthcare resource utilisation and outcomes, and potential uses to improve AKI follow-up care.</p> Graphical abstract <p></p>