We report a case of toxoplasmic encephalitis (TE) in a young woman without prior history of human immunodeficiency virus (HIV) infection. She was referred to our clinic with a diagnosis of multiple metastases following cerebral magnetic resonance imaging (MRI) revealing multiple ring-enhanced mass lesions. She had suffered from headaches for four weeks and there had been new onset of confusion and left hemiparesis. Soon after hospitalization, her neurological status rapidly deteriorated and she was operated for decompression. Pathology examination revealed TE and her blood samples were found to be HIV positive. We conclude that TE should be considered in the differential diagnosis of multiple lesions in sexually active individuals including cases without a prior history of HIV infection.