For this community-based sample of persons with SMI (n=907), there was a significant link between risk for violence and arrest and a person's perceived need for psychiatric treatment. People with SMI who were either arrested, violent, or both in the previous year were significantly more likely to endorse beliefs that negated the need for mental health treatment. Just over one-fourth of the sample reported either being arrested or behaving violently in the past year, which shows an enhanced risk for future arrest and violence for a significant number of people with SMI. Because the individuals in the current study were much more likely to deny the benefits of mental health treatment, they might be less motivated to adhere to treatment regimens. Several studies have shown that treatment involvement is related to reduced risk of arrest and violence in SMI individuals. Buttressing mental health care with interventions that target perceived need for psychiatric treatment are apparently critical for improving outcomes for individuals with SMI who are at risk for arrest and violence. Study participants were adults with psychotic or major mood disorders who were receiving treatment through public mental health systems of four States. Interviews were conducted with participants between June 1997 and December 1998. Instruments used in the interviews obtained information on participants' perceived need for mental health treatment, self-reported arrests and violence in the past year, demographics, and psychiatric symptoms. 2 tables, 1 figure, and 51 references