The atypical teratoid / rhabdoid tumour is a rare type of tumours of central nervous system appearing usually under 2 years of age, bearing a rather bad prognosis and it may cause serious differential diagnostic problem. The tumour is characterized histologically by the presence of the rhabdoid cells, immunohistochemically by vimentin, SMA, EMA positivity, the frequent presence of cytokeratin, GFAP positivity, but germ cell markers: AFP, hCG negativity, cytogenetically by aberrations of chromosome 22. The case of a one and half month old female infant is presented, who died 8 months after the appearance of the first symptoms. The diagnostic possibilities and the unsolved problem of the therapy are discussed.