In a review of 432 choroidal and ciliary body melanomas, histopathologic evidence of orbital extension was found in 45 cases (10.4 percent). The occurrence of orbital extension was influenced mainly by the cell type (P less than .05) and by the size of the choroidal mass (P less than .001). Local orbital recurrence occurred in 23 percent of cases with evidence of extrascleral extension. Survival rates were independent of cell type, pigmentation, and size and shape of the extension. Patients treated by exenteration had significantly better prognosis than nontreated patients or patients treated by chemotherapy, radiotherapy, or local excision (P equals .0002). Early exentration is the best treatment for choroidal melanomas with orbital extension.