A study of the speed of tumor regression in 127 uveal melanomas treated with beta-rays brachyterapy, since June 1983, allows a division into 2 groups: radiosensitive forms with a volume less than 50% in the following year, and radioresistant forms. Correlation between radio sensitivity and tumor cell type were obtained with intraoperative cytopunction, and showed the prevalence of epithelioid type. The results of enucleation indicate the prevalence of fusiform type inside the radioresistant tumor group. No precise correlation could be brought between death and the previous data, the most important negative criteria being the level of initial tumor height equal or superior to 7 mm.