Background: Relationships between dynamic risk factors for externalising problem behaviour and group climate were investigated in 151 adult in-patients with mild intellectual disability or borderline intellectual functioning in a Dutch secure residential facility. Method: Regression analysis was used to predict "total group climate score" and "Support," "Growth," "Repression," and "Atmosphere" subscales of the 'Group Climate Inventory'. Predictor variables were "Coping Skills," "Attitude towards current treatment," "Hostility," and "Criminogenic attitudes" subscales of the 'Dynamic Risk Outcome Scales'. Results: Less hostility predicted a better overall group climate, better support and atmosphere, and less repression. A positive attitude towards current treatment predicted better growth. Conclusion: Results indicate relationships of hostility and attitude towards current treatment with group climate. A focus on both dynamic risk factors and group climate may provide a basis for improving treatment for this target group.