The volume consists of up-to-date reviews and a selection of contributed papers on subjects including the structure and physical properties of molecular clouds, their role in the star formation process, their dust and chemical properties, molecular cloud surveys of the Milky Way, cloud evolution, problems in cloud mass determinations (a panel discussion and review), the CO properties of external galaxies, nuclei of galaxies as revealed by molecular observations, and galactic spiral structure as reflected by molecular cloud distributions. The abstracts of poster papers on these topics presented at the conference are also included. This book is both a valuable reference and a compendium of current knowledge in this field. It should be of special interest to all students and researchers who work on the physics of star formation, the interstellar medium, molecular clouds and galactic structure.