Two cases of choroidal osteoma (one bilateral) are reported, bringing the total number of cases in the English-language literature to 18; an additional 7 cases are known to the authors. This tumour, first described in 1978, arises in the inner third of the juxtapapillary choroid and consists of mature bone; it is likely an osseous choristoma. It transmits light in an unusual manner, small lacunae glowing with sclerotic scatter. If the bony plaque is peripheral its solid nature can be identified with scleral depression. Computerized tomography readily demonstrates the calcification and the pattern of bone density.