The T.E.A.C.H. project (Territory, Empirical research, Advocacy, Community, Hosting) aimed at preventing early school leaving by means of educational and training support for lower secondary students and by carrying out activities aimed at supporting parental skills in Como, Italy. The project involves Cometa Il Manto, a cooperative providing support for students, namely those affected by risk of dropout; in partnership with 3 lower secondary schools. The project includes the development of a social impact measurement system, to assess the effects of the actions on direct and indirect beneficiaries. For this reason, the Tiresia research center of the Politecnico di Milano, in collaboration with the partners, has defined and applied a social impact measurement methodology during the two years of the project.