To successfully examine the musculoskeletal system sonographically, one must understand the normal musculoskeletal anatomy and function and be aware of the abnormal processes that affect the musculoskeletal structures. The goal of this review article is to provide a systematic approach to sonographic examination of the musculoskeletal system. The general sonographic appearances of normal and abnormal muscles, tendons, ligaments, bursae, and nerves are reviewed. The article then applies this general information to specific clinical applications by reviewing the normal anatomy of and specific pathologic conditions that affect the shoulder, elbow, hand, wrist, hip, knee, ankle, and foot.