Acute renal failure (ARF) is defined as a syndrome in which there is a rapid progressive decline in renal function resulting in the inability of the kidneys to maintain homeostasis of the body fluids. Majority of the times it is reversible and the children recover completely. It can lead to residual compromise in renal function and progress to end-stage renal disease. ARF can be broadly classified into three main categories: prerenal, intrinsic renal and postrenal failure. Prerenal failure is the most common form of ARF in children. It is an oliguric state resulting from diminished blood flow to the kidneys from true volume contraction or from decreased effective blood volume. It is rapidly reversible if the systemic cause of hypoperfusion is corrected.