The concept of frontotemporal lobar degeneration comprises a heterogenous group of cortical dementias, including frontotemporal dementia, as the major clinical variant. Because of their highly variable clinical presentation, to establish the diagnosis of frontotemporal dementia could be a diagnostic challenge for the clinician. Here we report a 53 years old caucasian male patient who was admitted for hospitalization due to acute severe schizophrenia-like symptoms. The leading symptomatology comprised acoustic and bizarre optical hallucinations with euphoria and self-overestimation. Remission of the psychotic symptoms demasked the clinical picture of a rapidly progressive frontotemporal dementia with marked apathy, indifference, emotional blunting, loss of insight, change of personality and typical cognitive impairment. The diagnosis was supported by the results of cerebral MRI and FDG-18 PET. This first clinical manifestation of a schizophrenia-like syndrome in the 6th life decade implicates frontotemporal dementia as an important differential diagnosis of schizophrenic disorders in late life. In addition of basically thinking about frontotemporal dementia, a detailed medical history, cognitive testing, neuroimaging and eventually the evaluation of the further disease course are necessary to establish a diagnosis of frontotemporal dementia.