The toxoplasmosis is intracellular protozoan infection and becomes symptomatic under immunocompromised condition such as AIDS. But when a past history is not clear, correct diagnosis for toxoplasmosis becomes difficult.A 54 years old man presented with convulsive attack and left hemiparesis. Contrast enhanced T1 weighted image showed multiple ring enhancing lesions. Definitive diagnosis could not be obtained despite tumor biopsy performed for histological examination. Patient’s condition turned worse rapidly and passed away within 12days after second admission.We confirmed intracellular bradyzoites by thorough examination of pathological specimen and definitive diagnosis was obtained after the patient’s death.We should take into consideration of immunocompromised state such as HIV infection when we encounter a patient with multiple ring enhancing brain lesion.