Institutional violence in prisons and other corrections settings is a hazard to the security and wellbeing of staff and other offenders. However, the ability to systematically assess for acute, day-to-day aggression in these settings has not been widely developed. Staff assessing aggression in institutional settings ought to use risk assessment measures to aid professional judgement, and this research suggests a need for dynamic, acute risk assessment for aggression amongst New Zealand offenders. The Dynamic Appraisal of Situational Aggression (DASA; Ogloff & Daffern, 2006) was created originally for use amongst psychiatric inpatients. This research aimed to evaluate the use of the DASA for custodial staff in acute risk assessment and offender treatment in different prison units for its potential to fill this niche. Predictive accuracy of the measure in relation to aggressive behaviour was examined, and custodial staff were surveyed on the ease of administration, their perception of the measure’s effectiveness with their unit, and whether its addition improved offender management. Staff consisted of prison officers and a principle correctional officer in each of the three prison-based units, and custodial management staff at Tai Aroha. These staff nominated offenders (N = 19) on agreement of them being of highest management concern. Results found the DASA to demonstrate moderate predictive validity, with survival analyses showing high scores on the DASA were associated with highly aggressive offenders. Most staff identified the DASA as assisting in identifying those offenders that were a high risk for aggression. Implications for practice in corrections settings are discussed.