Ultrasound (US) is an efficient, rapid and inexpensive alternative to MR imaging for evaluation of a wide spectrum of tendon disorders of the wrist and hand. In traumatic injuries, complete and partial tears of the flexor and extensor tendons can be reliably identified with US. The US pattern shows a gap between tendon ends occupied by a hypoechoic interval due to debris or frayed residual fibers. The tendon ends may appear as stump-like structures or, following elongation trauma, are tapered. In closed injuries of the extensor tendons, US can recognize the cause of the tear, often due to bony spurs or attrition from surgical hardware. In flexor tendon injuries, US is particularly helpful in locating the two ends of the ruptured tendon as they may be retracted a considerable distance from the site of the tear. Dynamic scanning may help to distinguish partial from complete tears when the injury has occurred with an elongation mechanism. Postoperatively, dynamic scanning is a critical means to assess how the tendon glides and to rule out adhesions. Discontinuity in the tendon and detection of sutures floating freely in an empty sheath indicate a retear. Dynamic scanning is also reliable to demonstrate tendon instability related to the injury of annular pulleys (climber's finger), sagittal bands (boxers' knuckle) and retinacula (ECU instability). As a result of fibrosing degeneration, retinacula and annular pulleys may become thickened producing painful gliding, blockage or triggering of the underlying tendons. This most often occurs in the trigger finger and de Quervain disease. Some wrist tendons may be involved by specific overuse or degenerative changes. Among these conditions, US is an excellent tool for investigating the proximal (I-II compartment) and distal (II-III compartment) intersection syndromes and the FCR tendinopathy.