Acne vulgaris, is a chronic inflammatory skin disease that occurs when hair follicles are clogged with dead skin cells and oil from the skin .It is characterized by blackheads or whiteheads, pimples, oily skin and possible scarring. The aim of the present study is to evaluate the serum levels of high mobility group box 1 protein [HMGB1] in patients with Acne Vulgaris. This study was carried out on 60 patients suffering from ACNE VULGARIS and 20 apparently healthy individuals of matched age and sex as a control group. Patients were recruited from the outpatient clinic of Dermatology and Andrology Department of Benha University Hospitals during the period from JULY 2018 to DECEMBER 2018. HMGB1 serum levels in acne patients [32.67 ± 21.53] were significantly higher than the levels in control subjects [26.63 ± 5.77] [p=0.011]. Knowledge about early markers such as HMGB1 may facilitate diagnosis of acne disease and monitoring the treatment.