Cerebral toxoplasmosis nearly exclusively affects immunodeficient or immunocompromised patients. Mostly, it is a reactivation of latent toxoplasmosis. The pathogens, persisting in the reticuloendothelial system of heart and skeletal muscle cells, are causing a multifocal necrotizing encephalitis. The characteristic clinical features are organic psychosyndrome and focal neurological signs such as monoparesis, hemiparesis, aphasia, or seizures. Here we describe a 56-years-old patient who developed cerebral toxoplasmosis after receiving stem-cell transplantation treatment for acute myeloic leukemia, and we discuss the clinical features, differential diagnoses and therapeutic strategies.