Background: Warts are common benign epithelial keratinocytes proliferations caused by human papillomavirus (HPV) infection that may involve the skin and the mucous membranes Interleukin-17A (IL-17A), is a prototypic member of cytokines. It is recognized as an inflammatory cytokine and exerts its function mainly on myeloid cells and mesenchymal cells to induce the expression of certain kinds of chemokines, which in turn increase granulopoiesis and recruit neutrophils to the infectious site. Aim and objectives: The aim of the work was to evaluate the serum level of interleukin 17 in patients with viral warts and its correlation with the disease severity. Subjects and methods: this was a case control study, in which participants were  selected from the outpatient clinic of Dermatology, Venereology & Andrology department of Benha University Hospitals, carried on sixty patients of wart and thirty healthy subjects serving as a matched control subjects group. Serum IL17 was detected by ELISA Results: The results of the study revealed that there was high statistically significant difference between groups regarding IL 17 serum level where it was higher in wart patients' group. Conclusion: This study reported increased IL17 in sera of patients with warts irrespective of their clinical type (plane, plantar or common).This finding may denote that IL17 may have  a role in pathogenesis of viral warts.