The effect of pre-enucleation irradiation on the survival of patients with uveal melanoma was investigated in 140 patients. Of the patients, 42 received pre-enucleation cobalt external radiotherapy 2,000 cGy, in five fractions between 1981–1991. The control group consisted of 98 patients with uveal melanoma treated by enucleation alone between 1964 and 1994. The great majority of tumors in each group were confined to the choroid. The mean follow-up period was 58.3 months in the irradiated group and 61.6 months in the enucleation group. A comparison of the Kaplan-Meier survival curves of the patients managed by pre-enucleation irradiation and enucleation indicated no significant difference in survival between the groups. After 5 years of follow-up, the survival rates for the preoperatively irradiated group and the control group were, 86.5 and 86.8%, respectively. In both groups, women had a significantly better survival than men. It is more likely that pre-enucleation irradiation does not appear to improve survival in patients with uveal melanoma. The reason for this may be the micrometastases that occur before treatment.