The delusional misidentification syndromes are characterized by misidentification delusions of others or of the self. Aggressive ideas or behaviors often accompany these delusions. The relationship between delusional misidentification and dangerousness remains for the most part poorly understood. In the present article, we compare a group of dangerous individuals suffering from dangerous misidentification delusions with a group of dangerous individuals suffering from other types of delusions. Individuals with dangerous misidentification delusions were more likely to experience grandiose ideation, thought disorder, generalized hostility, excitement, general psychopathology, and a previous history of violence than dangerous delusional individuals with no delusional misidentification. The group with dangerous delusional misidentification syndromes was less likely to attack others with weapons than were the dangerous delusional group with no delusional misidentification.