A randomized controlled clinical trial of methanol-extracted residue of bacille Calmette-Guerin adjuvant treatment of posterior uveal melanoma was undertaken. Of 113 patients, 34 patients received adjuvant immunotherapy and 79 patients received no treatment. No difference in survival was observed between the adjuvant-treated group and the control group of patients. This study found that the size of the tumor was a highly significant risk factor for death caused by metastasis of uveal melanomas. The standard deviation of the nucleolar area of the neoplastic cells was a significant risk factor, even though patients with tumors composed of Callender's spindle-type cells were not included in the study.