We have developed highly viscous phantoms that include ultrasound scatterers in polyacrylamide gels, to be measurable by both magnetic resonance elastography and ultrasound elastography. The purpose of this study is to evaluate whether US-based shear-wave elastography (SWE) can measure elasticity accurately in a highly viscous, embedded phantom. Shear-wave speeds in the embedded hard parts were equivalent to the reference values. The reference values (RVs) of the embedded parts were measured by SWE in a homogeneous phantom whose content was the same as the embedded part. The RV of the background part was measured at a deeper area of the embedded phantom. The embedded part on the velocity-mode image was demonstrated as larger than the same part on the B-mode image. This phantom has the potential as a quality control phantom to mimic living tissues.