A 34-year-old Japanese woman had a melanocytoma of the optic disc with scattered pigment particles in the vitreous in the left eye in 1970. Fifteen years later, we noticed pigment dispersion on the posterior lens surface, iris root, and trabecular meshwork, which resembled findings often caused by ocular malignant melanoma. Because the melanocytoma of the optic disc had decreased in size and the number of dispersed pigment particles in the vitreous cavity was reduced, it appeared that the pigmented particles produced by partial necrosis of the melanocytoma had resulted in the pigmentation of the anterior segment.