The twenty-first International Laser Radar Conference (ILRC21) will be held in Québec City, Québec, Canada on July 8^th -12^th, 2002. This conference series brings together an interdisciplinary group of scientists, engineers and program managers to exchange ideas and results on technical developments and applications in the field of laser remote sensing of the atmosphere, earth, oceans and other planets. The ILRCs are held biannually under the auspices of the International Committee for Laser Atmospheric Studies (ICLAS). The last conference took place in Vichy, France, in July 2000. Over 250 researchers from more than 15 countries attended to hear and discuss 220 papers on a broad spectrum of subjects. These included the latest in lidar technology, the description of sophisticated ground-based, airborne and spaceborne systems, and many applications for the remote sensing and characterization of atmospheric aerosols and clouds, temperature and water vapor, wind, trace gases and atmospheric chemistry, radiative transfer, and transport processes.