A 26-year-old man presented with symptoms suggesting idiopathic orbital inflammatory disease. After a poor initial response to oral steroids, an orbital biopsy confirmed the diagnosis. A paucicellular lymphocytic infiltrate with areas of fibrosis was seen to replace normal tissue. With the development of exposure keratopathy and diplopia associated with eyelid retraction, lagophthalmos, and decreased motility, increasing doses of steroids and intralesional steroid injections were instituted without effect. On the basis of successful treatment of malignant lymphocytic lesions, he was treated with CyberKnife radiosurgery and rituximab. This resulted in symptom resolution with improved eyelid closure and motility. Eighteen months after treatment, he is essentially symptom-free, with almost complete radiographic regression of his disease process.