Asprosin, a novel glucogenic adipokine encoded by two exons (exon 65 and exon 66) of the fibrillin 1 (FBN1) gene, is synthesized mainly by white adipose tissue during fasting. Expressed in the central nervous system, peripheral tissues and organs, asprosin plays an important role in the regulation of various cellular and physiological processes such as hepatic glucose release in the liver, appetite stimulation in the hypothalamus, insulin secretion, apoptotic cell death, and inflammatory response. Asprosin, which may have an important role in ensuring body homeostasis, can be seen as a major therapeutic system in the pathology of some diseases. This chapter will discuss the newly discovered roles of asprosin that may contribute to future clinical diagnosis and treatment in metabolic diseases, including obesity, diabetes, polycystic ovary syndrome, and cardiovascular diseases.