The stifle joint presents a lot of soft tissues that cannot be imaged with radiography. Therefore, the use of ultrasonography to examine this joint may provide useful complementary information that can be essential for the diagnosis and management of many stifle conditions. This article presents the ultrasonographic technique to image the ligaments and tendons of the stifle, to show the reference ultrasonographic images and to present the main clinical conditions that can be diagnosed with this technique, used alone or in conjunction with other imaging modalities. The use of ultrasonography has considerably improved the diagnosis and knowledge of ligament and tendon injuries in the femoropatellar and femorotibial joints.