These 92 contributed papers give a comprehensive overview of Spanish astronomy. They include special reviews dealing with the cosmological evolution of star-forming galaxies, the nature of cosmic gamma-ray bursts, infrared astrophysics with ISO, and the distance scale after Hipparcos, with special emphasis on the development of the next generation of instruments to propel astrophysical research into the new century. The contents of these Proceedings thus reflect the broad interests of the Spanish astronomical community.