The XIX International Conference on Laser Spectroscopy, one of the leading conferences in the very diverse and still growing field of laser spectroscopy, was held in Hokkaido, Japan, on June 7-12, 2009. This volume, comprising a collection of invited contributions presented at the conference, will report on the latest developments in the area of laser spectroscopy and related fields: cold atoms and molecules, degenerate quantum gases, quantum optics, quantum information processing, precision measurements, atomic clock, ultra-fast lasers and strong field phenomena, and novel spectroscopic applications.