This study evaluated the effects of prolonged primary chemotherapy in retinoblastoma. The data for 27 eyes in 22 children who were treated for retinoblastoma with up to 13 cycles of primary chemotherapy was reviewed. The chemotherapy consisted of etoposide, vincristine, and either carboplatin or ifosfamide. In bilateral retinoblastoma, 1 eye was in each Ia, Ib, and Va, according to the Reese-Ellsworth classification, 2 in each IIa, IIIa, and IIIb, 4 in IIb, and 5 in IVa. Enucleation was performed in I in IIa and 1 in Va. In unilateral, 1 was in each IIa, IIIa, IVa, IVb, and Vb, and 4 in Va. Enucleation was performed in 8 with the exception of 1 in IIa. Complete regression was observed in 17 eyes (12 patients). There was no toxicity severe enough to delay treatment. Prolonged primary chemotherapy can be considered as an alternative treatment for retinoblastoma in III or less.