Patients with a psychotic disorder have certain symptoms, movement disorders resulting from the pharmacological effects of medication. Knowing about this is important to the patients’ dental treatment. A very small group will present with delusions about teeth or the benevolent or malevolent intentions of the dentist. Negative symptoms are an important characteristic of schizophrenic psychoses, meaning the absence of normal behaviour. Patients neglect personal hygiene and their lives have hardly any structure. They do not concern themselves with appointments, daily routines and social expectations. In such cases, prosthetic measures may be necessary. In addition, antipsychotic medications have adverse effects such as increased risk of caries, bruxism, oral and facial tardive dyskinesia, xerostomia, swallowing disorders and orthostatic hypotension. Suggestions for dental treatment and advice on how best to approach these patients are provided.