Plexus-chorioideus carcinomata or malignant plexus papillomas are very rare; only few cases have been described in the literature. A further observation is added now. In a 13-year-old girl, signs of brain pressure occured two weeks before admission to a hospital. Scintigraphy and vertebral angiography showed a process in the atrium of the right lateral ventricle which was removed by temporo-parietal trephination. The tumour had the size of an apricot and a reddish colouration, it proceeded from the plexus. After-irradiation with 5 000 rad. Six years after the operation, signs of brain pressure appeared again. Neuroradiologically the process was located in the right cerebellar hemisphere. After trephination of the cerebellum, the largely vascularised tumour, which appeared to originate from the tela choroidea of the 4th ventricle, could be removed. The further course was without pathological findings. Histologically, the typical criteria were found: Invasion of surrounding brain structures, loss of the regular papillary structure, malignisation of the cells and originating from the plexus choroideus.