Development of sensitive enzymatic methods for hydrogen peroxide is key for the quantification of several bioconstituents such as glucose, triglycerides, creatinine, and uric acid and so on. Hydrogen peroxide released by the oxidase enzymes are quantified by peroxidase enzyme involving spectrophotometry, fluorimetry, chemiluminisence, potentiometric sensing, amperometric, coulometric and such others. Authors in this line, present a short review on the assay of peroxidase. The entire review is divided into three different sections; first the importance of peroxidase clinically, secondly peroxidase chemistry with hydrogen peroxide and finally its role in the assay of bioconstituents.Keywords: Peroxidase; Clinical importance; Oxidase enzymes; Glucose assay; Nano sensors Role of Peroxidase in ClinicalAssays: A Short Review Peroxidase: A Clinically Important EnzymePeroxidases are widely distributed in nature especially in animal and plant cells. Peroxidases comprise of three major categories; plant peroxidases, animal peroxidases and catalases. These enzymes utilize hydrogen peroxide to catalyze the oxidation of variety of organic and inorganic compounds.