PURPOSE: The purpose of this study was to evaluate US and CT features of choroidal osteoma. MATERIALS AND METHDOS: US and CT scans of seven cases of choroidal osteoma occurring in six patients were retrospectively analyzed. We analysed US and CT findings with particular attention to the location, size, and shape of calcification associated with choroidal osteoma, and sought the possible cause of the tumor, if any. RESULTS: None of six patients had any possible cause related to choroidal osteoma. All of seven cases of choroidal osteoma were manifested as calcified mass which were located in the posterior wall of the eyeball near the juxtapapillary region. Calcification ranged in size from 1 to 2 cm and had curvilinear shape. Both US and CT were equally useful to evaluate choroidal osteoma. CONCLUSION: By depicting the characteristic calcification, US and CT are useful imaging modalities in evaluating choroidal osteoma.