--- - |2 Abstract Violence in correctional facilities is an important issue for both prisoners and prison staff. Risk assessment instruments have demonstrated their accuracy in predicting the risk of (re) offending and institutional violence in psychiatric settings, but less is known about their ability to predict violent misconduct in prison. The present study applied four risk assessment instruments (Structured Assessment of Protective Factors for violence risk, Historical Clinical Risk Management‐20, Psychopathy checklist – Revised, and Violent Risk Appraisal Guide) to 52 violent offenders in a Swiss prison in order to evaluate the instruments' predictive validities. Outcomes were instances of physically violent, other and any misconduct as recorded in prison files during the 12 months following the prisoners' assessments. Approximately 15% of offenders committed physically violent misconduct and approximately 42% committed any misconduct. The results show that mainly dynamic assessment tools are as good predictors of physically violent misconduct as mainly static assessment tools. Targeting dynamic factors could increase the effectiveness of interventions to reduce the risk of physical violence in prison. - Behavioral Sciences & the Law, EarlyView.