DIFFICULTIES IN TEACHING AND LEARNING ORGANIC CHEMISTRY IN HIGHER EDUCATION - A CASE STUDY IN TWO FEDERAL UNIVERSITIES. This research investigates difficulties associated to the curricular component Organic Chemistry I based on a study case of Chemistry undergraduate courses (Bachelor and Teachers education) in two Federal Universities in the Brazilian South region. The analytical process integrated official documents of the courses (pedagogic projects, students’ grades), questionnaires, interviews, and researcher’s logbook of classes. Results show that the students’ success in Organic Chemistry I is lower than the sum of failure, unattendance, and temporary cancellation rates altogether in the curricular component offered by the different teachers and institutions studied. A complex scenario is highlighted in relation to factors that affect learning and teaching processes in undergraduate Organic Chemistry courses. The subjects’ responses highlight difficulties related to specific contents, such as conformation and spatial visualization of molecules, stereochemistry, and reaction mechanisms; lack of concepts from High School; and individual habits and characteristics of teachers, students, or both, such as didactics, concentration, and engagement. The results report on the importance of rethinking strategies and methodologies in the context of Organic Chemistry I in Higher Education