BACKGROUND: Data on the long-term survival and renal function of patients with acute kidney injury (AKI) treated with continuous renal replacement therapy are scarce. METHODS: We investigated the 3-year survival and need for chronic dialysis in critically ill patients, who had survived an episode of AKI requiring continuous renal replacement therapy. RESULTS: A total of 206 ICU patients with AKI were randomized in a trial comparing haemofiltration versus haemodiafiltration. Of these, 95 (46%) survived at 90 days. Post-discharge information relating to 3-year survival and renal function was successfully obtained in 89 (94%) of the patients. Of the 89 patients studied, chronic kidney disease (CKD) was present in 32 subjects from the onset, and CKD developed de novo in 25 patients following AKI. End-stage renal disease (ESRD) developed in 9 patients (of whom 8 had pre-existing CKD) and 29 patients died. Three-year survival was 67% overall; the mortality at 3 years was 50% for those with pre-existing kidney disease, and 71 and 82% for those with de novo and without CKD, respectively. CONCLUSION: After an episode of AKI necessitating a continuous renal replacement therapy, rapid progression to ESKD is commonly observed in patients with pre-existing chronic renal impairment. Medical care with an emphasis on nephroprotection is necessary in these patients.