The influence of neuroleptic drugs on body temperature regulation is w
ell established. Even with atypical neuroleptic drugs such as clozapin
e, hyperthermia has been observed as well as the malignant neuroleptic
syndrome. It is likely that the influence of clozapine affects the im
mune response. A case is reported in which afebrile angina tonsillaris
and endocarditis developed, as a result of high-dosage therapy with c
lozapine over several years. Besides the special features of the cours
e, differential diagnosis, therapy and possible influence on the body
temperature and the immune response are discussed.