A wide‐angle, crossed‐beam laser Doppler scattering configuration is described. This configuration is optimized for measurement of electrophoretic mobility of blood cells. It is easy to align and maintain aligned and is stable against microphonic disturbance. The optimum scattering angle for blood cells is shown to be in the range of 25°–45°, a condition that is easy to implement with this configuration and within the geometrical constraints imposed by the use of narrow gap rectangular electrodes for applying an electric field.