A 58-year-old man with asthma, chronic sinusitis, and nasal polyposis presented with a 1-day history of headache, blurry vision, and vomiting. His blood pressure was 170/88 mm Hg. Neurological examination was significant for right homonymous hemianopsia. Initial laboratory results were remarkable for peripheral blood eosinophilia (25%; normal, 0%-8.5%). A computed tomographic scan of the head showed an intracranial hemorrhage in the left occipital lobe (Figure 1A). Emergent evacuation of the intracranial hemorrhage was performed, and brain tissue was sent for routine biopsy. On postoperative day 2, he developed cough and shortness of breath. Oxygen saturation was 90%. A general examination revealed coarse crackles bilaterally on chest auscultation. Diffuse alveolar hemorrhage was noted on a computed tomographic scan of the chest (Figure 1B). He was intubated for respiratory failure. Further workup revealed an elevated myeloperoxidase–antineutrophil cytoplasmic antibody (>1000 EU; normal, 0-21 EU). Brain tissue pathologic study results showed an intense eosinophilic vasculitis (Figure 2A and B). A diagnosis of Churg-Strauss Syndrome (CSS) was made. The patient received pulse cyclophosphamide infusion and a 5-day course of pulse intravenous methylprednisone (1000 mg/d). His respiratory parameters improved, and he was weaned off the ventilator. He was discharged and prescribed oral prednisone and monthly cyclophosphamide infusions. Brain magnetic resonance imaging (Figure 2C) obtained 6 weeks later showed a small residual left occipital hematoma, with no evidence of chronic ischemic sequelae or microhemorrhages. At the 3-month follow-up, the patient’s neurological examination showed a residual right homonymous hemianopsia. He was able to ambulate independently. His language functions were intact, with no aphasia or difficulty in reading or writing.