An effective implementation approach is crucial for successful integration of structured risk assessment instruments into practice. This qualitative study explored barriers and facilitators to the implementation of the Short-Term Assessment of Risk and Treatability: Adolescent Version (START:AV) in a Dutch residential youth care service. Perceptions of staff members from various disciplines were gathered through focus group interviews at three consecutive occasions. After inductive coding of the interview extracts using thematic analysis, the identified codes were linked to the consolidated framework for implementation research. Through this framework, factors that influence an implementation project can be organized into multiple domains and constructs. In the present study, staff members described implementation barriers related to characteristics of the risk assessment instrument, staff, and the implementation process. In addition, features of the setting were frequently mentioned as hindering the implementation, such as hierarchy, culture, communication, as well as implementation climate and readiness for change. Staff members also identified multiple facilitators, such as experienced advantages of the START:AV compared to the previous risk assessment practice and positive beliefs about the instrument. The article concludes with recommendations for successful implementation of structured risk assessment instruments in forensic-clinical practice.