StarGuides 2001 is the enlarged and updated version of a long line of directories published since 1978 (see e.g. Heck 1995 & 1997) and gathering together all practical data available on associations, societies, scientific committees, agencies, companies, institutions, universities, etc., and more generally organizations, involved in astronomy and space sciences. Many other types of entries have also been included such as academies, advisory and expert committees, bibliographic services, consultants, data and documentation centres, dealers, distributors, funding agencies and organizations, journals, manufacturers, meteorological services, museums, norms and standards offices, planetariums, public observatories, publishers, research institutions in related fields, software producers and distributors, etc. Besides astronomy and space sciences, related fields such as aeronautics, aeronomy, astronautics, atmospheric sciences, chemistry, communications, computer sciences, data processing, education, electronics, energetics, engineering, environment, geodesy, geophysics, information retrieval, management, mathematics, meteoro­ logy, optics, physics, remote sensing, and so on, are also covered when justified. The basic philosophy of this directory (and of other products in the Star*s Family) is to provide practical data which one seeks to always have at ones disposal. Over the years they have proved to not only be valuable auxiliaries for improving national and international relationships, but also to be efficient tools for helping laypersons and public bodies to contact organizations easily.