Europe’s shortage of STEM skilled labour force is well documented, and the lack of STEM-skilled labour is predicted to be “one of the main obstacles to economic growth in the coming years”. There is a real need, at the European level, for innovative approaches to increasing the motivation of pupils towards STEM subjects and for offering teacher training into new ways of introducing science to the classroom. Additionally, there is still work to be done in improving the image of scientists at the societal level and demystifying science in general, if academic institutions are to attract much needed talent in their various fields. To meet these challenges, BRITEC proposed introducing research into classrooms through Citizen Science activities, co-designed between schools and research institutions, initially in the partner countries and with the long-term view of massive uptake in Europe and beyond. Citizen Science is a relatively new way of conducting scientific research, by enlisting the support of citizens into the data collection, data analysis, data interpretation and/or (in rare cases) data presentation. BRITEC proposed introducing the Citizen Science (CS) approach in schools as a way of connecting schools with the world of research and increasing the interest of young Europeans in STEM subjects and careers. BRITEC offers schools and research institutions a multi-stakeholder collaboration model, easy to replicate, to support the promotion and uptake of STEM studies and careers. To build this model, BRITEC suggested a bottom-up approach, including three complementary blocks of activities, which build on each other to develop a set of exemplary practices and guidelines for the implementation of Citizen Science in the classroom and to ensure their large-scale dissemination and uptake: 1. A foundational phase, including desk research into existing national and international citizen science initiatives and the development of a set of guidelines of introducing research into schools. 2. A Piloting Phase, during which teachers and researchers from each of the four participating countries (Belgium, Greece, Poland and Spain) co-defined and ran a number of Citizen Science projects in their countries. Exemplary practices feed into the Citizen Science toolkit for the large-scale implementation of CS in countries all across Europe. 3. The large-scale deployment phase, including the development and running of a Massive Open Online Course and a set of recommendations for policy makers, meant to ensure that the good practices resulted from the project jump from the initial set of participants to other schools and universities/research institutions interested in bringing innovation to STEM teaching. Through these actions, BRITEC aimed to: [1] expose pupils to real-life research actions and allow them to develop skills and competencies related to STEM through learning by doing [2] strengthen the dialogue between research institutions and schools, and the role of educational institutions in their local and regional environments [3] raise the profile of teachers by allowing them to become research coordinators in their schools [4] ensure that good practices which support the development of STEM skills are adequately disseminated to a large population of teachers throughout Europe and beyond.The main participants of the BRITEC activities were: teachers, researchers and students. Additional group benefiting from the BRITEC outcomes: heads of schools, parents, local communities, ministries of education, policy makers in the field of education. We reached directly over 1300 persons and assume that additionally ca. 6000 students benefitted from the BRITEC programme.