Biomarkers are "biological parameters that can be objectively measured and evaluated, which act as indicators of normal or pathogenic processes, or of the pharmacological response to a therapeutic intervention". Renal failure can be broadly divided in acute and chronic renal diseases, two classes of renal pathology that are well distinct each other, not only on the basis of duration and reversibility of loss of kidney function, but also because of their different aetiopathological processes and their different histopathological characteristics. Unlikely, the conventional measures used for monitoring kidney function are not ideal in the diagnosis of neither acute or chronic kidney diseases and has impaired our ability to institute potentially effective therapies. Therefore, researchers are seeking new early, predictive, non-invasive biomarkers that can aid in the diagnosis for both acute and chronic diseases. These biomarkers will be useful for assessing the duration and severity of kidney disease, and for predicting progression and adverse clinical outcomes. This review article summarized our current understanding of the acute and chronic renal diseases and discussed the most promising biomarkers for facilitating early detection and predicting clinical outcomes.