The diagnostic criteria for schizophrenia and the diagnostic criteria for personality disorders refer to the same dimensions of mental functioning, except for the presence of typical psychotic symptoms in schizophrenia (hallucinations, delusions and catatonic behaviours). Since schizophrenia is a psychosis with a predominantly chronic course, with exacerbations and steady course periods, a simultaneous diagnosis of personality disorders, which are also “permanent” in nature, and a significant part of which affect the same areas of mental functioning, in the same patient is at least controversial. Although therapeutic interventions in patients with schizophrenia are mainly based on pharmacotherapy, psychotherapy and work with the patient’s family are also important. Since pharmacotherapy is virtually ineffective for personality disorders, psychotherapy is the main form of management. This however does not constitute a justification for a simultaneous use of these two diagnoses in the same patient.