Warts are benign epidermal proliferations of the skin and mucosa caused by human papilloma viruses (HPV) which include a large group of DNA viruses that commonly affect humans. Recurrent skin and anogenital warts may be disfiguring, impose a considerable psychological burden, and are a frequent cause of medical office visits.The aim of this work is to study the expression of Cathelicidin in Verruca Vulgaris and clinical response of wart before and after intralesional injection of vitamin D3.This case control study included 20 subjects of both sexes suffering from verruca vulgaris and ten apparently normal individuals as a control group recruited from the outpatient clinic of Dermatology, Venereology and Andrology Department of Benha University Hospital in the period between January 2018 to May 2019. Approval of the Local Ethics Committee on Research inVol.ving human subjects of Benha Faculty of Medicine and written informed consents of participants were obtained before samples collection. The results of the study showed expression of Cathelicidin in warts but not in normal skin. Good clinical response in verruca vulgaris after injection of vitamin D3.