The clinical characteristics and microscopic features of the biopsy specimens of 66 patients with orbital lymphoid tumors were analyzed with respect to clinical outcome (disease remaining localized to the orbit or developing associated extraorbital lesions). The patients' average age was 63 years, and their tumors had a marked tendency to arise in the anterosuperior orbit. No clinical or radiographic findings helped to distinguish the cases of localized disease from disseminated disease. The lesions were divided microscopically into three categories: reactive lymphoid hyperplasia (16), atypical lymphoid hyperplasia (38), and malignant lymphoma (12). Extraorbital lesions developed in 25%, 50%, and 75% of cases, respectively. The five-year mortality rates were also significantly different for each type of lesion: 6%, 19%, and 58%, respectively.