The influence of the properties of the size distribution of seeding particles on the results of laser Doppler anemometry (LDA) velocity measurements in the vicinity of a large velocity gradient downstream of an aerodynamic shock is studied numerically. Accounting for the differing velocity lag of particles of different sizes the average velocity and the pertaining rms values are determined in the relaxation region within which the particles adjust towards the changed flow velocity downstream of the shock. It is shown how the average velocity and the rms value depend on the mean particle size and the density of the particle material. It is demonstrated in a numerical simulation how the LDA system’s ‘‘amplitude limit,’’ which can offer a means of excluding the contribution of large particles towards the experimental results, affects the average velocity and the rms value to be measured in the relaxation region. Experimental LDA data of velocity measurements across an oblique shock are presented. A good qualitative agreement of the numerical and the experimental results is found.