The Historical Clinical and Risk Management scale (HCR-20) is a structured clinical judgment tool used to assess risk of violence in secure settings. But the scale does not account for difficulties typical of patients with autism spectrum disorder, which are thought to contribute to their engagement in violent behaviors. The present study is a preliminary investigation of the association between risk assessment and physical and verbal violence in patients with autism spectrum disorder in a secure psychiatric hospital. Scores from the third version of HCR-20 (HCR-20V3) and violent episodes at three and six months following the initial assessment were extracted from an electronic record. The results support the use of the HCR-20V3 to assess the risk of overall and physical violence but not verbal aggression. Future studies are needed to identify which factors are associated with violent behaviors in patients with autism spectrum disorder.