Abstract Background Vitiligo is an acquired, a progressive, multifactorial, depigmenting disorder characterized by the appearance of circumscribed white macules in the skin due to chronic, progressive loss of functional melanocytes in the epidermis. Aim of the Work We aimed to evaluate GNLY- levels in stable and active vitiligo patients in comparison to healthy controls. Patients and Methods A case-control study which was carried out on 66 subjects: 22 patients with active vitiligo, 22 with stable vitiligo, and 22 age and sex-matched controls. All patients were recruited from the Dermatology Outpatient Clinic of Ain Shams University hospitals during the period from February 2021 to May 2021. Results We found a statistically significant difference between vitiligo patients and controls regarding GNLY levels with higher GNLY-levels among cases as compared to control. There were no statistically significant relations between GNLY-levels and gender or age of patients, family history, distribution or duration of vitiligo as well as activity or severity of vitiligo disease. This suggests that GNLY has an important role in vitiligo pathogenesis regardless of the activity, severity, and different disease characteristics. To the best of our knowledge, our study was the first study that measured GNLY-level in vitiligo patients and compare it with controls. Also, compared GNLY level in stable vitiligo versus active vitiligo. Conclusion Our findings supported the possible role of GNLY in the pathogenesis of vitiligo. However, measurement of GNLY level can not be used as a discriminating marker between stable and active vitiligo.