Background: Acne vulgaris (AV) is an inflammatory condition of pilosebaceous unit that is common in adolescents and young adults. The pathogenesis of AV is multifactorial, one of which is inflammation. Interleukin-23 (IL-23) has an important role in the activity of T helper 17 (Th17) cells that produce IL-17 in chronic inflammation.Objective: To determine the correlation between serum IL-23 levels and AV severity in men.Methods: This is an analytical observational preliminary study with a cross-sectional design involving 15 male subjects with AV who were divided into groups of AV severity based on Lehmann’s criteria. The subjects were examined for serum IL-23 levels. Data were analyzed using Spearman’s Rho non-parametric correlation test to determine the correlation between variables.Results: Mean IL-23 serum levels in men with AV was 111,05 ± 115,27 pg/ml, with mild AV was 210,57 ± 122,038 pg/ml, moderate AV was 103,65 ± 91,15 pg/ml and severe AV was 18,94 ± 15,76 pg/ml. There is a significant correlation between IL-23 serum levels and AV severity in men. (p = 0,001). Serum IL-23 levels decreased with increasing AV severity (r = -0,756).Conclusion: There is a strong negative correlation between IL-23 serum levels and AV severity in men.