Immunological changes reported in patients with schizophrenia may play an aetiological role in these disorders. Further, immunomodulatory medications can influence the symptoms of psychiatric disorders. Antipsychotic agents such as clozapine may act therapeutically through the modulation of the immune system and also lead to side effects in that domain.Both the understanding and factual foundations of immunological concepts and immunological therapies of schizophrenic disorders have changed throughout the history of medicine. These are important considerations in psychiatry where diagnostic, nosological and therapeutic complexity is the norm. The article exemplarily presents publications of the psychiatrists such as Julius Wagner von Jauregg, Lewis Campbell Bruce and Friedrich Ostmann as well as neuropathologist Hermann Lehmann-Facius and haematologist William Dameshek.