Reported herein is a case of 62-year-old man who complained of blurred vision and ocular pain in his right eye. The patient was diagnosed with choroidal melanoma complicated by neovascular glaucoma (NVG) and total retinal detachment, and he underwent enucleation of the eye. The isolated tumor was 2.5 x 2.5 cm in size. It was accompanied by intratumoral calcification, and consisted of epithelioid and spindle melanoma cells. There were a variety of microvessels in the stroma of the iris. The expression of thymidine phosphorylase (dThdPase), an angiogenic factor, was examined immunohistochemically. Cytoplasmic immunoreactivity for dThdPase was more prominent in the epithelioid cells than in spindle tumor cells. Another case of choroidal melanoma without NVG had less marked immunoreactivity. These results suggest that the production of dThdPase by melanoma cells correlates with the pathogenesis of NVG.