Carpal tunnel syndrome is the most common nerve entrapment syndrome. The majority of cases are due to compression or irritation of the median nerve in the carpal canal. It is diagnosed clinically, often being confirmed by an electromyogram, while ultrasonography criteria have become increasingly useful for the diagnosis. Ultrasonography is better tolerated, less expensive, yet just as effective as other diagnostic methods. It provides a good indication of the severity of the condition and it allows anatomical variants to be discerned. In light of this, for a number of medical professionals it is the first-line examination. In terms of therapeutic use, ultrasound can be used to guide infiltrations. In case medical treatment is unsuccessful, release by transection of the flexor retinaculum is generally done surgically as an open procedure or by endoscopy. A new minimally invasive percutaneous treatment to release the nerve based on ultrasonography guided or ultrasound surgery appears to be a promising alternative, however, to conventional open surgery or endoscopic treatments.