Background: Vitiligo is an acquired depigmenting disorder due to destruction of melanocytes, many hypotheses have been suggested for its pathogenesis. One of these hypotheses suggest that there are autoimmune and endocrine dysfunction involvement. The involvement of vitiligo with thyroid autoimmune diseases, with the increased prevalence of auto antibodies including thyroid auto antibodies in vitiligo support the hypothesis. Patients and Methods: 50 Libyan patients under same age and gender with vitiligo, and 50 controls . Patients were excluded if they had a history of thyroid, or other autoimmune diseases. Data on age, onset of illness, duration and disease activity were determined . Serum T3, T4, TSH , and antibodies to TPO and TG were measured in both vitiligo patients & controls. All patients and control subjects underwent thyroid ultrasonography. Results: Fifty patients with vitiligo and their 50 matched controls were studied. More than half of the patients (52%) were females and 48% were males, their mean of age was 40 ± 11 years, and the duration of vitiligo was 11± 9 years. Vitiligo vulgaris type was the most common form seen in 68% of the patients, and 42% reported at least one family member affected with vitiligo. Family history of thyroid disorder was seen in 20% of the patients. Thyroid functional abnormalities were significantly seen more in patients than control subjects. The frequency of TG and TPO thyroid autoantibodies was significantly higher in vitiligo patients than in healthy controls (P < 0.01). Abnormal thyroid ultrasound study was seen in 18 (36%) of the patients compared to 6 (12%) of the control subjects (P < 0.05). Conclusion: Our findings pointed to a significant association between vitiligo and thyroid autoimmunity and showed that testing the level of thyroid autoantibodies is relevant in vitiligo patients.