Lymphoproliferative disorder (LPD) sometimes occurs in immunosuppressive patients. B-cell proliferation is predominantly seen in patients with LPD and T-cell proliferation is rare. We here report two patients with T-cell LPD involving the central nervous system (CNS). A 7-year-old boy developed increased intracranial pressure and computed tomography showed a ring-enhanced mass lesion in the right frontal lobe. A 10-year-old boy developed gait disturbance and magnetic resonance imaging showed a non-enhanced lesion in the left parietal lobe. Radiological findings could not differentiate CNS-LPD from other intracranial diseases. Only histologic examination could diagnose LPD in both cases, and Epstein-Barr virus associated RNA was found in the infiltrated T-cell of the latter case. Although chemotherapy with antitumor agents was effective for remission of LPD in both cases, both patients died 3 years after their operations. As CNS-LPD shows rapid progression and frequently results in fatality, this disease requires immediate histologic diagnosis followed by extensive chemotherapy.