This volume consists of papers selected from the proceedings of the Fifth International Symposium on Applications of Laser Techniques to Fluid Dynamics, held at the Calouste Gulbenkian Foundation in Lisbon from 9 to 12 July, 1990. The contributions provide an overview of new applications of laser-based techniques to fluid dynamics and experiments which demonstrate new methods and quantify accuracy. The techniques include laser-and phase doppler anemometry, particle-image velocimetry, Rayleigh and Ramanspectroscopy, laser-sheet visualization, fuorescence, and particle sizing by refraction and diffraction. The applications include boundary layers, jets and waves, separated flows, swirling flows, engines, turbomachinery, furnaces, and combustion.