A patient with clinical and radiographic findings initially suggesting a neoplasm was diagnosed as having Hodgkin''s disease. Computerized axial tomography demonstrated profound diffuse decreased density similar to that seen in cases of cerebral edema or leukomalacia. Cerebral angiography showed blood vessels with a beaded appearance. A diagnosis of granulomatous angiitis was made on the basis of brain biopsy specimens. Viral cultures were negative. Skin testing revealed poor responses to antigens. The patient improved dramatically following a combination of radiotherapy and steroid therapy. Resolution of the low-density abnormality seen on serial EMI scanning and resolution of the vasculitis demonstrated in the post-therapy brain biopsy specimen was dramatic. This was the 1st case of granulomatous angiitis of the brain diagnosed during life, and it demonstrated the value of radiation and steroid therapy for relief of neurologic symptoms.