The delusional misidentification syndromes are characterized by a misidentification delusion of the self and/or others. Delusional misidentification syndromes frequently occur in psychotic disorders such as schizophrenia, psychotic disorder due to general medical condition, or psychotic disorder not otherwise specified. On rare occasions these syndromes may be associated with manic states secondary to bipolar disorder, schizoaffective disorder, or general medical conditions. The delusional misidentification syndromes may also be associated with verbal and physical aggression. In this article we present three cases of dangerous delusional misidentification associated with mania. We will discuss the role that mania may have in the genesis of dangerous delusional misidentification.