Background: The loss of melanocytes from the epidermis causes vitiligo, a common acquired skin condition that shows up as distinct white spots on the body. Its pathophysiology is closely linked to autoimmunity. The imbalance of peripheral blood lymphocytes, mostly cytotoxic T cells (CD8+ cells) and helper T cells (CD4+ cells), is associated with the death of melanocytes. Aim: This study aimed to determinate CD4+/CD8+ ratio in vitiligo patients and control, to assess the correlation between CD4+/CD8+ ratio and activity and severity of vitiligo and to correlate between the levels of these T-cell subsets with activity and severity of the disease. Patients and methods: This case control study was conducted at Dermatology Department, Suez Canal University hospital from May 2023 to June 2024. This study included 44 vitiligo patients and 44 apparently healthy controls. All participants underwent full history taking, full physical examination and investigations including Complete blood count and flowcytometry analysis for memory T cells (CD3, CD4 and CD8). Results: A significant correlation was detected between CD3+/4+ (absolute) and vitiligo area severity index (VASI) score, lymphocytes % and absolute lymphocytes in addition. There was a significant correlation between CD3+/8+ (absolute) and lymphocytes % and absolute lymphocytes in patients group. However, no significant difference was recorded between active and non-active patients regarding relative and absolute CD3+ and absolute CD3+/4+.   Conclusion: This study demonstrated that CD3+, CD4+ and CD8+ may be implicated in the pathogenesis of vitiligo.