Choroidal metastases and melanomas are the most common intraocular neoplasms. Choroidal metastases may appear clinically similar to other amelanotic tumors, and the diagnosis may be difficult in the absence of a history of extraocular malignancy. Ultrasonography, using A- and B-mode criteria, offers an opportunity for high accuracy in the diagnosis of choroidal tumors. However, a considerable overlapping of ultrasonographic parameters, such as tumor solidity, vascularity, and choroidal excavation, has been demonstrated for choroidal melanomas and metastases. We have found that choroidal metastases are characterized by a significantly lower height-to-base ratio than melanomas, whereas reflectivity is significantly higher in metastases. Thus the combined use of height-to-base ratio and reflectivity provides a highly significant differentiation between choroidal melanomas and metastases. This observation has further improved the diagnostic value of ultrasonography in the differentiation of choroidal tumors.