A 27-year-old woman with metamorphopsia was diagnosed with choroidal osteoma (CO); concurrently choroidal neovascularization (CNV) was also suspected. Neither fluorescein angiography (FA) nor indocyanine green angiography showed signs of CNV. A course of oral corticosteroids improved the symptoms, but when it was interrupted, both, the ophthalmoscopic and the FA findings showed a well defined CNV. Two years following green argon laser photocoagulation the CNV is still inactive.The clinical and angiographic heterogeneity of the CO can delay the diagnosis and treatment of an associated CNV.