Melanoma isolated to the iris is rare and can present with a distorted pupil. This is a case report of an 81-year-old asymptomatic man, who had a large pigmented element in his left iris through 30 years. Because of involvement of the angle the tumour was excised with the ciliary body, and histopathologic examination revealed an iris melanoma. The aim of this report is to underscore the clinical signs of an iris melanoma and when surgery is needed.