Objective: To present a simplified approach to management of retinoblastoma using basic clinical features. Design: In a prospective, nonrandomized, single-center clinical trial, 158 eyes of 103 patients with retinoblastoma were managed with 6 cycles of chemoreduction (vincristine sulfate, etoposide, and carboplatin). The eyes were classified according to the Reese-Ellsworth classification and were also grouped on the basis of clinical features as follows: group 1, tumor only; group 2, tumor plus subretinal fluid; group 3, tumor plus focal seeds (3a, focal subretinal seeds; 3b, focal vitreous seeds); group 4, tumor plus diffuse seeds (4a, diffuse subretinal seeds; 4b, diffuse vitreous seeds); and group 5, neovascular glaucoma or invasive retinoblastoma. Main Outcome Measure: Treatment success (avoidance of enucleation and external beam radiotherapy). Results: According to the Reese-Ellsworth classification, chemoreduction was successful in 100% of group la, 100% of group Ib, 86% of group IIa, 100% of group IIb, 91% of group IIIa, 100% of group IIIb, 50% of group IVa, 77% of group IVb, 50% of group Va, and 27% of group Vb. There was erratic correlation of the Reese-Ellsworth classification with treatment success. In contrast, the simplified grouping system displayed a smooth, nonerratic correlation for treatment success, with 100% success for group 1, 91% for group 2, 59% for group 3, and 12% for group 4 (group 5 always managed by primary enucleation). When all 6 subcategory groups were analyzed, there was consistent correlation for treatment success of 100% for group 1, 91% for group 2, 68% for group 3a, 54% for group 3b, 17% for group 4a, and 11% for group 4b. Conclusion: This practical approach to retinoblastoma using basic clinical features is predictive of treatment success for eyes in which modern conservative therapy for retinoblastoma is used.