A directionally sensitive, three-velocity-component laser Doppler anemometer has been developed. It permits straight-line scans through three-dimensional flows to obtain space-time velocity information, and has a lower signal-averaging bias than point-wise measurements. A Ronchi ruling is employed to create a horizontal fringe pattern and a dual Bragg cell is used to produce sets of moving vertical fringes. It is also shown that a proposed three-beam scheme does not produce a fringe pattern moving in the on-axis direction that would measure the on-axis velocity components. The Doppler frequency is independent of the position of the receiving optics, and only one photomultiplier tube is needed to receive the signals for all three velocity components. Measurements made on a stationary solid object as well as in a dispersion of particles in water show that signals with low noise level and high fringe visibility are obtained.