An 11-year-old boy admitted with a right cervical mass was found to have Hodgkin disease. On admission, he also had right Horner syndrome and severe cerebellar ataxia. Cranial MRI revealed marked cerebellar atrophy. He was treated with chemotherapy consisting of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD), in addition to radiotherapy. Three months after initiation of therapy, he had a partial remission of tumor. Neurologic symptoms improved dramatically after chemotherapy started. Hodgkin disease should be included in the differential diagnosis of children with cerebellar findings and Horner syndrome.