To evaluate the efficacy and safety of transpupillary thermotherapy in treating choroidal melanoma. Methods and Patients: To perform transpupillary thermotherapy, infrared diode laser energy at 810 nm was used with a beam diameter of about 3 mm and 1-minute exposure time. All 50 patients had choroidal melanoma. We performed transpupillary thermotherapy in 21 tumors that had responded insufficiently to 800 Gy ruthenium 106 brachytherapy; it was combined with 800 Gy 106 Ru brachytherapy for 10 tumors greater than 5 mm in height and with 600 Gy for 19 tumors 5 mm or less in height. Results: Allbut1tumorexhibitedreductionintumorheight within a mean follow-up of 20.5 months (range, 6-49 months). In 41 eyes (82%), the tumor flattened completely. Visual acuity was 20/60 or better in 43 eyes (86%) before treatment and in 14 eyes (28%) at the last examination because of radiation vasculopathy. Neovascular glaucoma developed in 1 eye, and total retinal detachment developed in 2 eyes. Tumor recurrence was observed in 1 patient. Conclusions: Although long-term results are necessary to properly appraise this new therapy, transpupillary thermotherapy may be useful as a complementary modality to brachytherapy.