Not only is the anatomy of the hand and wrist complex, but also its pathologic conditions are quite diverse. Although plain radiographs, CT, arthrography, and MRI have traditionally been used to evaluate the hand and wrist, ultrasound is beginning to take its place alongside these more traditional imaging modalities and is being ordered with increasing frequency by orthopedic surgeons. This article reviews the pertinent gross anatomy and sonographic technique used to scan the hand and wrist and also describes the sonographic findings associated with the most common hand and wrist pathologic conditions. These include soft tissue tumors, tenosynovitis, tendinous and ligamentous injuries of the hand, Dupuytren's contracture, foreign bodies, and carpal tunnel syndrome (CTS). (C) 2000 by W.B. Saunders Company.