INTRODUCTION: Continuous renal replacement therapy (CRRT) is an important treatment in critically ill children with acute kidney injury (AKI). Over the past decade, CRRT has been the preferred method of renal replacement therapy. We compared children with CRRT-treated adults with AKI in terms of return of kidney function (renal recovery (RR)) and mortality. Furthermore, we compared RR and mortality in children above and below 10 kg. MATERIAL AND METHODS: The present study was a prospective cohort study of all paediatric patients treated with CRRT over a period of 13 years at the paediatric intensive care unit (PICU), Odense. We obtained data on gender, age, weight, diagnosis, indication for CRRT, need for vasoactive drugs, days using CRRT, days in the PICU, mortality and RR. RESULTS: A total of 36 critically ill children were recorded. The overall mortality was 39%. The primary diagnosis was sepsis with multiple organ failure. 80% started CRRT due to a combination of anuria/oliguria, high azotemia and fluid overload. Among the 22 surviving patients, eight had continuing renal impairment at discharge from the PICU. CONCLUSION: CRRT is an effective treatment for the haemodynamically unstable child with AKI. There was no difference in mortality between the group of children above and below 10 kg. In this study, mortality was lower in children than in adults with CRRT-treated AKI. In comparison with adults, fewer children regained kidney function.