Delusional jealousy is a known risk factor for violence and homicide, but little is known about its prevalence in psychiatric disorders. We therefore reviewed retrospectively the psychopathological symptoms at admission and discharge, assessed with the AMDP system, of all patients admitted to the Psychiatric Hospital, University of Munich, Germany, from January 2000 through December 2008 (n=14,309). We identified 72 cases of delusional jealousy (0.5% of the whole sample). The prevalence was highest in schizophrenia and other psychoses (1.3%), and more of the patients with delusional jealousy were men (43 of 72, 59.7%). One-fifth (15 of 72, 20.8%) of the patients with delusional jealousy were aggressive at admission (vs. 6.2% of the total sample). We conclude that delusional jealousy is a comparatively rare phenomenon that is most frequent in schizophrenia and related psychoses. Quite a number of affected patients are aggressive, which may indicate a risk of future violence.