Many employers know the value of positive mental wellbeing but do not know how to promote it. For example, the 2018 Business in the Community report Mental Health at Work found that only 30% of managers have received training on mental wellbeing at work. Therefore, the objective of this review is to identify what - training for managers - is effective and acceptable to help them to: understand mental wellbeing. support and promote their employees’ mental wellbeing. recognise employees who experience, or are at risk of, poor mental wellbeing. responding to their employees’ mental wellbeing. The relationship between training for manager and health outcomes of employees is complex and can be influenced by a range of factors including work stressors and work-related resources. Managers may influence some of these stressors, but this also depends on the organisational, structural, cultural and other environmental conditions.