 Given todays high prevalence of common mental disorders and related sick leave among teachers an urgent need exists for a more sustainable working life for this professional group. One way of doing this is by improving schools social and organizational risk management. Recent reports have shown that many schools in Sweden however lack a structured approach to the management of social and organizational risks. In 2015, we launched the first Swedish occupational health guideline to support a structured prevention of social and organizational risks at the workplace with the aim of preventing common mental disorders. The long-term goal of this study is to support the implementation of this guideline within schools in order to improve social and organizational risk management and in doing so reduce risk factors for mental ill-health and related sick days. The objective of the study is to fill the current research-to-practice gap by conducting a cluster-randomized controlled trial that compares the effectiveness of two implementation strategies for implementing the guideline in schools. The strategies that will be compared are training ARM 1 versus training in combination with implementation teams and workshops ARM 2. Our hypothesis for the study is that schools that receive support in implementing the guideline through combined strategies are more responsive to working in a structured and systematic manner with the management of social and organizational risks than schools that only receive training. The trial will be conducted in 30 primary schools in three municipalities in Sweden. All schools have agreed to participate. The primary outcomes are adherence to the guideline implementation effectiveness and self-reported exhaustion among schools personnel intervention effectiveness; the secondary outcomes are risk factors for mental ill-health and absenteeism. Data will be collected at baseline, 6, 12 and 24 months by mixed methods i.e. survey, focus-group interviews, observation, and register-data. 