Sonoelastography is a novel ultrasound (US) tool of portraying the strain properties of biological tissue. The carpal tunnel syndrome (CTS) may cause structural and elastic distortion of the median nerve (MN). The aim of this study was to evaluate B- mode US and strain elastography in patients with CTS compared to healthy subjects and study their correlations with nerve conduction studies (NCS). Methods: This case-control study included 100 wrists of 57 patients clinically diagnosed as CTS and 110 non-diseased wrists of 55 apparently healthy controls. CTS patients underwent NCS. For both patients and control groups, the MN cross-sectional areas (CSA) at the wrist, the wrist/ forearm ratio (WFR) and the flattening ratio (FR) were obtained along with assessment of the MN echogenicity, and mobility. Elasticity of the MN was determined using strain elastography. Results: In the CTS patients, the MN at the wrist was highly significant stiffer (p