The purpose of this study was to determine teachers' educational needs regarding school education projects within the scope of Erasmus+ programme. In the study, the case study method, one of qualitative research designs, was used. The participants were determined using the snowball sampling method, and eight secondary school teachers took part in the study. The research data were collected via semi-structured interviews and analyzed using the inductive analysis method. The results of the analysis revealed that the teachers had certain knowledge about the processes of planning, implementation and evaluation of the projects and that they did not acquire the necessary related skills at all, though. It was also found that the group work process and lack of related knowledge, skills and experience were among the factors making the functioning of the process difficult and that professional development was not fully achieved. All these results demonstrate that teachers are need of an in-service training which focuses more on the steps of the application process and on the integration of the objectives of the process into the curriculum and which aims to help acquire the related skills considering the functioning of the process as a whole.