This volume includes revised and extended versions of selected papers presented at the Tenth International Symposium on Applications of Laser Techniques to Fluid Mechanics held in Lisbon in July 2000.The papers describe instrumentation developments for velocity, scalar and multiphase flows and results of measurements of turbulent flows, and combustion and engines. Focus is placed on laser-Doppler anemometry, particle sizing and other methods for the measurement of velocity and scalars, such as particle image velocimetry and laser induced fluorescence. The application of laser techniques to scientific and engineering fluid flow research was emphasized, but contributions to the theory and practice of laser were also considered where they facilitate new improved fluid mechanic research.