This is a retrospective review of treatment results in 63 children with retinoblastoma (RB) who received therapeutic irradiation from January 1975 to June 1988. Patient ages ranged from birth to 5 years with a mean age of 12.5 months. Three treatment groups were identified. In Group A, episcleral plaque was the only irradiation modality. In this group, 24 patients and 25 eyes with tumors of Reese-Ellsworth Stages I to III, and selected Stage VB tumors were irradiated using eye plaques. Twenty-two of 25 (88%) eyes are without evidence of disease (NED), and all patients are alive. Two eyes were enucleated for recurrent RB. Two of 23 eyes developed minimal cataracts. In Group B, external-beam was the only irradiation modality. Twelve patients with 21 involved eyes comprise this group. Thirteen eyes received EBRT alone. Seventy-seven percent of 13 eyes have NED. Four eyes developed cataracts. Three of 13 eyes required enucleation for progression of disease; one of these was Stage IVA and two of them were Stage VA. For Group C, external-beam plus episcleral plaque was used. Twenty-seven patients and 51 eyes with advanced retinoblastoma were included in this group. Episcleral plaque was used in 29 eyes as a salvage procedure for recurrent RB, or in selected cases was used as a boost after initial external beam irradiation. Fifteen of 29 eyes (52%) remain with NED with useful vision, and nine developed cataracts. Enucleation was performed in 14 eyes for recurrent RB. The authors conclude that radiation therapy has a major role in the management of RB due to its ability to control even advanced disease, allowing preservation of vision in a significant number of patients.