Ultrasound elastography is a relatively new imaging modality that can measure tissue elasticity quantitatively by using different techniques. With the development of technology, kidney elasticity measurements can be performed accurately and quickly using ultrasound. Nowadays, kidney stiffness is used not only in fibrosis but also in the characterization of focal lesions, staging of metabolic kidney damage including diabetes mellitus, gout disease, etc.., and evaluating renal damage in urinary tract abnormality. However, kidney is a unique tissue and has a complex internal architecture. Therefore intrinsic or extrinsic factors such as perfusion, urinary pressure, anisotropy, depth of kidney, and hydronephrosis may affect the viscoelasticity of the kidney.