Pooling data from four samples in which 1,882 men were assessed for acts of interpersonal violence, we report on 120 men whose self-reported acts met legal definitions of rape or attempted rape, but who were never prosecuted by criminal justice authorities. A majority of these undetected rapists were repeat rapists, and a majority also committed other acts of interpersonal violence. The repeat rapists averaged 5.8 rapes each. The 120 rapists were responsible for 1,225 separate acts of interpersonal violence, including rape, battery, and child physical and sexual abuse. These findings mirror those from studies of incarcerated sex offenders (Abel, Becker, Mittelman, Cunningham-Rathner, Rouleau, & Murphy, 1987; Weinrott and Saylor, 1991), indicating high rates of both repeat rape and multiple types of offending. Implications for the investigation and prosecution of this so-called "hidden" rape are discussed.