Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by intense itching and eczematous lesions. Interleukin 17 (IL-17) has been implicated in the pathogenesis of AD, but its expression in the skin tissues of AD patients compared to normal controls remains to be fully elucidated. Understanding the role of IL-17 in AD is crucial for the development of targeted therapies and improved management strategies. This study aimed to assess the level of tissue IL-17 in AD compared to normal control before and after topical mometasone fumarate cream. Methods: This diagnostic interventional case-control study was carried out on 30 patients with AD (Group A) and 30 age and sex-matched healthy subjects (Group B) as controls. Comprehensive assessments were performed, including evaluation of disease severity using the SCORAD index and measurement of subjective symptoms. Skin tissue biopsies were collected before and after the application of topical mometasone fumarate. IL-17 levels were assessed through histopathological examination. Results: Before treatment, AD patients had significantly higher tissue IL-17 when compared with controls (314.51±19.60 vs 146.39±15.75pg/ml; p<0.001). After treatment, AD patients had significantly higher tissue IL-17 when compared with controls (209.19±21.49 vs 146.39±15.75 pg/ml; p<0.001). The mean IL-17 in tissue significantly decreased after treatment with topical mometasone furoate when compared with before treatment (209.19±21.49 vs 314.51±19.60 pg/ml; p<0.001). Conclusions: The present study revealed significant elevation of tissue IL-17 in patients with AD when compared with controls. In addition, treatment with topical mometasone furoate had a significant lowering effect on tissue IL-17 in AD patients.