A series of 6 patients with primary T-cell lymphomas of the central nervous system (PTCLCNS) is presented. The clinical, histological and immunohistological findings are shown. The lesions were infratentorial in the 34% and sopratentorial in the 66% of the cases. Of the 5 cases with an available follow-up only one died in the first year after diagnosis and one is alive and well after 42 months. These data agree with those of others series of PTCLCNS in the literature. In conclusion our data and those of the literature suggest that immunophenotyping should routinely be carried in primary non-Hodgkin's lymphomas of the CNS (PNHLCNS), because the T-cell forms run a more favourable course than the B-cell varieties.