The clinical and pathological data of 66 patients with orbital cavernous hemangioma are presented. This tumor occurs in females more frequently than in males, and has its peak incidence in early middle age. Visual disability results from a high degree of relative hyperopia or from optic-nerve compression. Postural or temporal variation is proptosis is not characteristic. Multiple cavernous hemangiomas are rare, but may occur simultaneously or separated by long intervals. In this series, incompletely excised lesions did not cause recurrent proptosis. Relative hyperopia may persist, in spite of complete removal of the tumor. Improved preoperative localization with modern techniques appears to be reducing the morbidity associated with surgical excision of the lesion. A local hemodynamic disturbance may initiate proliferation of vascular channels that undergo progressive ectasia. Growth of the lesion may occur intrinsically by the budding-off of capillary channels from cavernous spaces into the interstitium. Clinical and pathological findings fail to demonstrate any relationship between this lesion and capillary hemangioma of childhood.