Background: When melanocytes cease to operate, vitiligo develops. It is a skin and mucosa depigmentation condition. Any area of the body can develop well-circumscribed white macules or patches in this disease.  Approximately 1-2 percent of the population is affected by Vitiligo. Suppression of tumorigenicity 2 (ST2), a newly discovered member of the interleukin-1 (IL-1) family, acts as a receptor for the IL-1 receptor-like 1 protein (also known as IL-1RL1) while also acting as a ligand for the interleukin-1 receptor-like 1 protein (also known as IL-1RL1) and suppressing tumorigenicity 2. Objective: To study Interleukin 33 (IL-33) in generalized and localized vitiligo patients and to assess their relationship with disease activity. Conclusion: Vitiligo could be associated with increased serum levels of IL-33, which could help as predictor marker of disease activity in vitiligo.