Attention to vocational training and professional orientation responds to national priorities of the Ministry of Education and territorial priorities in Cuba. It is recognized as a process aimed at preparing students for the self-determination of their profession, which allows them to access university studies in accordance with their individual and social aspirations. The above mentioned allows identifying the need to strengthen this process in the Pre-university Vocational Colleges of Exact Sciences in order to favor the direct entrance of students to careers in exact and technical sciences. This book offers a theoretical analysis and an empirical evaluation of this process in the context of the Pre-university Vocational Institute of Exact Sciences in Cuba. Result of the project: The professionalization of the teacher in the Pre-university Vocational Institute of Exact Sciences; associated to the Sectorial Program "Cuban Educational System. Perspectives of development" of the Ministry of Education.