A pregnant 33-year old woman developed nystagmus and cerebellar ataxia. A tumor in the roof of the fourth ventricle was diagnosed. The tumor was subtotally removed using microneurosurgical techniques. The histopathological diagnosis was choroid plexus papilloma (CPP). Twenty-one months later, the tumor recurred and was reoperated. Histologically the tumor displayed now increased mitotic activity and pleomorphism. Radiation therapy of the neuroaxis was performed. Within 59 months, the CPP recurred 3 more times with neuroradiological evidence of extensive spinal seeding. After several palliative irradiations, including 2 gamma-knife boosts, the patient was referred to chemotherapy. She was treated with CCNU (Lomustin) 100 mg/m2 orally (12 cycles, cumulative dosis 1440 mg/m2). Within 42 months, there was no new local recurrence and spinal seeding showed significant regression. Clinically the patient improved and stabilized, but needs continuous support because of persisting severe gait ataxia. The course of disease in our patient provides evidence for therapeutic efficacy of CCNU in recurrent CPP.