Nevus of Ota is characterized by the presence of hyperpigmentation in the skin areas innervated by the first or the second branches of the trigeminal nerve. Women are affected three times as often as men. Although nevus of Ota is a congenital disorder, it can be seen in puberty or adulthood. Herein a case of nevus of Ota was reported accompanying iris heterochromia and rare iris mammillation. Because of the relationship between iris heterochromia and iris mammillation with glaucoma and especially uveal melanoma, all the patients with nevus of Ota should be monitored closely with regular ophthalmologic examination