A fourth case of bilateral retinoblastoma (RB) associated with pinealoma was identified among 56 patients with heritable RB. Using life-table analysis, the association was 5.6% 2 years after RB diagnosis. Retinoblastoma-pinealoma (RB-P) was uniformly fatal in this series and in 40 additional patients described in the literature. Ninety-five percent of patients with RB-P had bilateral RB, a positive family history of RB, or both. All patients with pinealoma presented with symptoms of increased intracranial pressure due to obstructive hydrocephalus. The advanced stage of the tumors at diagnosis may contribute to their uniform lethality. The incidence of a positive family history of RB in patients with pinealoma was higher than expected (62% of patients), which may be related to earlier surveillance and treatment of patients with positive family histories of RB.