Pemphigus vulgaris is an autoimmune blistering disease. An association of pemphigus vulgaris with vitiligo or Hashimoto's thyroiditis has not been reported before. We reported a 38 yr-old female patient with Hashimoto's thyroiditis and vitiligo who eventually developed pemphigus vulgaris on vitiliginous lesions. A genetic predisposition or a local event on vitiliginous skin may be responsible for the development of pemphigus in this patient.