Tetrasomy of chromosome 3q is a genetic condition in which there are 4 copies of the long arm of chromosome 3. In pure tetrasomy, all cell lines in the body are affected; however, in the mosaic form of the syndrome, a result of a nondisjunction event, tetrasomy exists in some tissues but not others, resulting in a patchy phenotypic manifestation. Tetrasomy of chromosome 3q has been reported to manifest with skin pigmentary abnormalities, skeletal abnormalities, and neurodevelopmental anomalies,1-3 but, to our knowledge, few details of ophthalmic manifestations have been reported. We describe posterior segment findings in mosaicism of tetrasomy of chromosome 3q.