The best teacher is the one who comes to perform in itself that attempts to make on others.(Demosthenes) Abstract the characteristics of educational scenarios according to the reality of the present, they force to redefine the functions of university teachers, which must manifest a constant proactive in their performance. Above all, be updated according to the requirements that are needed in order to provide the knowledge that involve their students, delve into this reality, according to the selected profession and guarantee a professional exercise that favors everyone, specifically in his specialty. It is therefore necessary to determine what should be these functions and try it to achieve the goal of providing a reliable teaching, which ensures the training of professionals required to meet the challenges and generate the changes that are needed. Performance keywords, functions, tasks, commitment, obligations, results basic annotations, functions have said, that the This demand for teachers each day with greater epistemological budget, willing to take the diversity of knowledge, leadership, be more creative and innovative in facilitating the process of teaching and learning, thus adapt to the new vision of the University of the 21st century. Reality, shows every day, the need that modern teachers, properly use the tools and knowledge needed to current scenarios require, in order to ensure that student under their charge, purchase not only adequate to the challenges, generate transformations that are necessary according to their profession, but that step to new knowledge favouring the institutions where labora, to the community, to the country. . The connection of functions, it is very interesting to take into account the valuable contributions that we bequeathed and indicates Pere Marques Graells and to transcribe in part, on what today should be: diagnosis of needs.