We attempt to demonstrate, according to the present-day conditions of public libraries in Mexico City, how illogical is thinking about the creation of a large library, which will use up most of the financial budget required for the improvement of current libraries. Three methodological approaches where used: the analysis of the information included in the bibliographical sources as well as in the periodical publishings (newspapers and magazines), the direct observation to compile data as well as being acquainted with the current situation of the libraries, and the application of tests to the staff in the community libraries that belong to the different districts of Mexico City. As a result, it was stated that many libraries require better installations, as electricity service is inadequate, and libraries lack adequate plumbing (rest rooms). In general, libraries need the essential elements to create a pleasant environment. So, it was concluded that there are essential and important necessities in community libraries, which have not been taken into account because of the lack of financial resources. In consequence it would be illogical to invest in the creation of the new large library Jose Vasconcelos. CONACULTA should establish priorities based in the real needs of the Public Libraries National Network (Red Nacional de Bibliotecas Publicas).