Musculoskeletal ultrasonography (MSUS) has been refined by improved examination techniques and higher frequency transducer technology. Sonography is the modality of choice in the screening of tendon disorders. The accuracy in diagnosing tendon lesions has improved with better understanding of the sonographic anatomy and the pathophysiology of tendons. The sonographic appearance of tears, tendon dislocations, tendinitis, tenosynovitis, insertion tendinopathy, ganglion cysts, and bursitis is described. Normal variants that mimic tendon disease are shown. The tendons of the shoulder, elbow, wrist, hand, knee, ankle, and foot are considered.