Psychological wellbeing of residential staff has substantial impact on the therapeutic milieu. These staff members are regularly confronted with aggression and other stressors, leading to low work satisfaction, burn-out and high staff turnover. The aim of this study is to evaluate the efficacy of Non-violent Resistance (NVR), a method for professionals to cope with aggressive behaviour of children and adolescents in residential care, with respect to work climate, living group climate, and aggression. NVR was implemented using a quasi-experimental stepped wedge design at three sites providing child and adolescent residential care in the Netherlands. Work and living group climate was assessed seven times, every three months. In addition, the average number of aggressive incidents before and after NVR implementation were described. A total of 519 work climate assessments by 186 staff members and 260 living group climate assessments by 124 children were collected. Multilevel analysis showed significant positive effects on the following elements of work climate: team functioning, satisfaction, task-significance, having a shared vision and on commitment at one of the three participating sites. Living group climate changed, but not in the expected direction. At two sites the living group climate was more repressive after NVR implementation. Aggressive episodes were low before and remained low after NVR implementation. These findings provide limited evidence that the implementation of NVR has a positive influence on work climate in residential settings. This study is a first step in investigating the relationship between NVR and improving work climate, living climate and aggression in the turbulent practice of residential youth care. The manner that NVR is implemented seems to have a substantial effect on the efficacy of NVR. Optimising the implementation along with assessing and improving readiness for change and more research on the possible influence of contextual factors is needed to fully evaluate the efficacy of NVR in residential setting.