Background: By interacting with children, group care workers shape daily living environments to influence treatment. Current literature provides little knowledge about the content of youth residential care. Objective: In this study, a questionnaire called the Group care worker Intervention Checklist was developed. Method: Group care workers completed the questionnaires for 212 children placed in youth residential care in the Netherlands. Results: Factor analyses revealed three constructs: controlling, warmth/support, and autonomy granting. Reliability of these scales proved to be good. Controlling was associated with Externalizing Behavior Problems while both Warmth/Support and Autonomy Granting were associated with Internalizing Behavior Problems. Conclusions: These findings imply that group care worker interventions can be reliably measured and are related to child problem behavior.