Carpal Tunnel Syndrome is the most common entrapment neuropathy. Treatment for carpal tunnel syndrome varies according to the severity of the disease, ranging from conservative treatment to surgical intervention. Conservative treatments such as steroid injection within carpal tunnel are helpful for most patients with mild to moderate carpal tunnel syndrome. However, in the case of the most commonly used steroid injection, the effect is short or limited within 6 months. In this paper, I will review ultrasound-guided nerve hydrodissection for carpal tunnel syndrome, which has recently attracted attention.