Expedited research on Obesity has confirmed that, adipose tissue is highly active in secreting a variety of proteins, one among them is visfatin. It was originally identified as Pre B cell Colony Enhancing Factor (PBEF), to be secreted by the lymphocytes and can act as a cytokine with immune regulatory action. Besides, it acts as Nicotinamide phosphoribosyl transferase (Nampt), an enzyme involved in the NAD+ salvage pathway. It has been shown to help in the regulation of glucose homeostasis, but whether it binds to insulin receptor and exerts insulin mimetic activity is still a controversy. Visfatin has antiapoptotic activity and has a regulatory role in inflammation. Several studies have identified changes in the circulatory levels of visfatin in diseases. Notable among them are obesity, diabetes mellitus, kidney diseases and bone disorders. It is a molecule of clinical relevance and could be a promising biomarker with diagnostic and prognostic significance.