Background The Emerald project's focus is on how to strengthen mental health systems in six low- and middle-income countries (LMICs) (Ethiopia, India, Nepal, Nigeria, South Africa and Uganda). This was done by generating evidence and capacity to enhance health system performance in delivering mental healthcare. A common problem in scaling-up interventions and strengthening mental health programmes in LMICs is how to transfer research evidence, such as the data collected in the Emerald project, into practice. Aims To describe how core elements of Emerald were implemented and aligned with the ultimate goal of strengthening mental health systems, as well as their short-term impact on practices, policies and programmes in the six partner countries. Method We focused on the involvement of policy planners, managers, patients and carers. Results Over 5 years of collaboration, the Emerald consortium has provided evidence and tools for the improvement of mental healthcare in the six LMICs involved in the project. We found that the knowledge transfer efforts had an impact on mental health service delivery and policy planning at the sites and countries involved in the project. Conclusions This approach may be valid beyond the mental health context, and may be effective for any initiative that aims at implementing evidence-based health policies for health system strengthening.