A case of bilateral primary choroidal melanoma is described. To our knowledge, this is the first reported case in Spain. On admission of a 70-year-old man for a choroidal melanoma in the right eye, an asymptomatic tumor was detected in the periphery of his left eye. A-scan ultrasonography, fluorescein angiography and diascleral transillumination supported the diagnosis of choroidal melanoma in both eyes. The right eye was enucleated. Histology confirmed a choroidal melanoma of the mixed type. The left eye was treated with laser photo-coagulation and an episcleral plaque of ruthenium-106. Careful systemic evaluation produced no evidence of a primary tumor or metastatic disease elsewhere in the body. Because of the impossibility, in most cases, of obtaining histological confirmation in both eyes, and the tendency of choroidal melanomas to metastatize late, we suggest that the criteria of independent origin (two separate cell types and tumors separated in time) are not necessary in cases of presumed bilateral choroidal melanoma.