BACKGROUND: The aggression of hospital patients costs money and affects outcomes. Most methods to assess risk for aggression are developed for adults. This study recommends the use of a predictive tool, the Dynamic Appraisal of Situational Aggression–Youth Version (DASA-YV) to improve accuracy in identifying aggression risk in youth. AIMS: To determine if aggressive behavior of youth is better predicted with DASA-YV versus instinct. We sought to validate the feasibility of DASA-YV and determine its predictive validity for aggressive behavior in a youth-specific psychiatric hospital population, which could lead to prevention of aggression and improve interventions or outcomes. METHOD: After establishing interrater reliability of the DASA-YV, a 6-month pilot study with a prospective validation design compared aggressive behavior outcomes predicted with those that occurred within the next 24 hours. RESULTS: DASA-YV was found to be reliable and valid in predicting aggression in a youth population. CONCLUSIONS: Predicting aggression with the DASA-YV tool demonstrates a useful best practice application for psychiatric nurses that positively affects safety.