miRNAs are small, endogenous, post-transcriptional regulators of gene expression. AKI (acute kidney injury) of various aetiologies, including trauma, sepsis and IRI (ischaemia/reperfusion injury) in the context of kidney transplantation, or drug toxicity, has a high morbidity and mortality rate and presents a significant burden to health services worldwide. AKI primarily affects the renal cortex, in particular PTCs (proximal tubular epithelial cells). Current research demonstrates causality between G2/M cell cycle arrest of PTCs and AKI. Recent findings from our laboratory and others presented in this review implicate miRNA regulation of the cell cycle in the pathology of AKI.