Consistent with the findings of other studies, the current study found that nonforensic patients had higher rates of committing assaults in State psychiatric hospitals than either group of forensic patients; however, those forensic patients with the same demographic and clinical characteristics as nonforensic patients who committed assaults in the hospital were just as likely to commit assaults. This suggests that techniques for treating and managing assaultive behaviors in psychiatric hospitals should be the same for both forensic and nonforensic populations because of their sharing of factors linked to assaultive behavior. Forensic and nonforensic patients with similar demographic and clinical variables could be housed together without posing a differential risk of violence to the other party. Also, the study's findings of low assault rates among forensic patients should promote policy and practice discussions about admission and release policies. Other data are needed in order to determine whether some forensic patients are being unnecessarily hospitalized and whether community-based options can comply with public-safety requirements. This study was a secondary analysis of data collected from a statewide, annual, cross-sectional survey of all patients in Missouri's four long-term psychiatric hospitals on July 1, 1997. Assaults were measured as the total number of physical assaults against others during the 1-year period before the July 1, 1997, survey. Demographic variables measured were age, sex, race, and marital status. Clinical variables measured included the number of prior admissions to a psychiatric facility, whether the commission of an aggressive act was one reason for the current admission, and the length in months for the current hospitalization. 3 tables and 40 references