Aim. The aim of this study is to discuss diagnostic and therapeutic challenges in a patient with a mutation in the gene responsible for the development of Huntington's disease (HD) who presented schizophrenia-like psychotic symptoms. Method. A case report. Results. A 35-year old man with genetically-confirmed HD who developed significant behavioural changes that occurred many years prior to the outbreak of choreic movements. There was a close temporal relationship between an onset of discrete involuntary movements and schizophrenia-like psychotic symptoms (delusions of persecution, reference and bodily change, as well as auditory pseudohallucinations of threatening and commanding voices). At admission (subsequently to a suicidal attempt) he was ambivalent, ambitendent and - periodically agitated. Pharmacotherapeutic regime of olanzapine (20 mg qd) and amisulpridc (400 mg qd) led to a gradual improvement of the patient's mental status. Conclusions. HD should always be included in the differential diagnosis of psychotic disorders. Patients with HD can exhibit various psychopathological symptoms (including psychotic ones) prior to the outbreak of movement symptoms. Both neurologists and psychiatrists should take part in the therapeutic process. Atypical antipsychotics seem to be effective in the discussed group of patients (although the evidence body consists mainly of scarce, low-quality data).