Abstract Background Mental health as a public health issue warrants a comprehensive prevention-oriented approach whereby capacity building as well as a multisectoral and life-course approach are crucial. The ‘Capacity-building on mental health: multidisciplinary training programme and exchange programme for health professionals,’ project enhances and improves the capacity of professionals across Europe in the field of mental health. Various professionals are targeted 1) health professionals working in the mental health sector, 2) teachers and educators working in the educational setting, 3) social workers working in various community settings and 4) prison staff. Objectives To understand the needs, gaps, obstacles in capacities, competencies, and to build upon existing programmes a mixed methods study, adopting a convergent parallel design is conducted to design and develop the programme. First, a literature review is conducted complemented with interviews, focus group discussions and a survey among various stakeholders to enrich the data. The training will be piloted in The Netherlands, Spain, Czech Republic, Croatia, Finland and Austria. Thereafter it will be rolled out in the 21 remaining EU countries as well as in Norway, Iceland and Ukraine. Results Various gaps and competencies identified from different perspectives build a solid fundament for a comprehensive multidisciplinary training programme tailored to the needs of various professionals within the mental health arena. Preliminary results show that 98 multidisciplinary training programmes exist, with about half containing training materials and limited reports on evaluation. Conclusions The comprehensive needs assessment will assure a multidisciplinary training programme is suitable and relevant for various professionals to ensure a well-designed capacity-building programme. Key messages • Various gaps and needs among various professionals exist. • A comprehensive study strengthens alignment of training to needs and gaps among various professionals.