Co-teaching is an internationally recognized strategy for its possibilities on teacher professional development and student learning, which involves considerable transformations in the classroom. The Chilean Ministry of Education implemented this strategy through the School Integration Programs, pointing to it as a tool for improving the quality of education. Consequently, this article focuses on the evaluation of co-teaching practices through a descriptive and mixed study based on the interview and the focus group. The latter became an occasion for understanding and reflecting on teachers' pedagogical and curricular management concerning co-teaching practices. From this evaluation, we identified both difficulties regarding time management for teaching preparation and the prevalence of isolated work on the part of the classroom teacher and the differential educator. The instrumented improvement actions strengthened pedagogical leadership, teaching design, interpersonal relations, teacher professional development and student learning.