Acute Kidney Injury (AKI) is a complication in critical illness caused by kidney damage by dehydration, blood loss due to major surgery / injury and the use of drugs. One medical treatment is to do renal replacement therapy even though it is still classified as controversial. Based on this statement, does RR give bad or good impact? How to handle patients with AKI? This study used electronic data base as a method by reviewing some previous article published from another medical journal The results showed that intensive renal support in critically ill patients with acute renal injury did not reduce mortality or improve renal function recovery. If renal replacement is performed earlier in AKI it may have a beneficial effect on survival, but this is only based on heterogeneous studies of variable quality and with only 2 randomized trials. Other studies regarding the timing of renal replacement were grouped into an initial ICU (62 days), delayed (2-5 days), late (N5 days). The timing of kidney replacement therapy with serum urea showed no significant difference. The adverse impact of failure from renal replacement is the occurrence of acute kidney failure due to a series of kidney replacement therapies, causing a higher mortality of 62.8%. From the explanation above, it can be seen that the impact of renal replacement for critically ill patients with acute kidney injury still presents a risk in its implementation so it still requires in-depth research in reducing the risk of kidney replacement therapy.