Most primary CNS lymphomas (PCNSL) are B-cell neoplasms; T-cell lymphomas are quite rare. The authors report two young patients with T-cell PCNSL who had a complete response to chemo- and radiotherapy but developed recurrent disease and died 11 and 13 months from diagnosis. The prognosis of T-cell PCNSL may be worse than that of comparable B-cell tumors.