Choroidal osteomas caused visual symptoms in four healthy young women. A positive 32P test led to enucleation and histopathologic confirmation of the diagnosis in one patient. The characteristic ophthalmoscopic findings in these patients included the following: (1) slightly and irregularly elevated, yellow-white, juxtapapillary, choroidal tumor and well-defined geographic borders; (2) diffuse and mottled depigmentation of the overlying pigment epithelium; and (3) multiple small vascular networks on the tumor surface. A diffuse mottled pattern of hyperfluorescence in the area of the tumor occurred during the early and later stages of angiography. The tumors were ultrasonically dense, and the orbital tissue behind them was rendered silent. The tumors were visible on routine orbital x-ray films and computerized tomograms. The latter study demonstrated the tumors as having the consistency of normal bone.