The ultrasonic behavior of glass‐filled xanthan solutions was studied in the frequency range 5–105 MHz as a function of filler particle size and filler concentration. The glass beads were characterized by measuring the particle size distributions. Unfilled xanthan solution exhibited one relaxation process in this frequency range. The frequency dependence of excess attenuation exhibited two peaks. One of these peaks was in the same frequency range as the relaxation for the unfilled solution and has been interpreted as being due to a modification of the background molecular relaxation. The other process was a complex combination of thermal, viscous, and scattering effects, with multiple scattering being the dominant mechanism at higher concentrations. Although the system studied here was different from an emulsion or suspension in that the continuous phase was viscoelastic, the ultrasonic behavior could be qualitatively explained using existing theories for emulsions and suspensions.