Acne is a longstanding inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production, altered keratinization, inflammation, and bacterial colonization of hair follicles by Propionibacterium acne [1]. Apelin is a newely discovered adipocytokine secreted by white adipose tissue and couples with the APJ receptor with the highest affinity. Apelin and the APJ receptor are found in pancreatic islet cells and found to have a role in energy metabolism. Many researches show that apelin has a role in  glucose homeostasis regulation,  insulin secretion, and increasing insulin sensitivity [2].The aim of the work was to evaluate the serum level of Apelin-13 in patients with acne vulgaris .Serum apelin was measured in 40 patients with moderate to severe acne vulgaris and 30 healthy controls using enzyme-linked immunosorbent assay (ELISA).  Serumlevels of apelin13 in patients with acne vulgaris was found to be higher than in healthy controls (p value <0.005).In Conclusion Serum apelin13 has a role in the pathophysiology of acne vulgaris patients.