A 31-year-old woman was diagnosed as having a malignant melanoma of the choroid in the right eye. Twenty months later her 7-year-old son was diagnosed as having retinoblastoma in the right eye. Both diagnoses were confirmed histopathologically after enucleation. A chromosomal study revealed normal karyotypes in the son. The family history was positive for cancer of the stomach. The implications of this rare association are discussed.