Magnetic resonance imaging and a thorough understanding of its interpretation in the diagnosis and management of injuries to the ligaments about the knee is an essential skill for orthopedists. The goal of this review is to provide a description of the native and injured anatomy through magnetic resonance imaging and its correlations, when appropriate, as seen through the arthroscope at the time of surgery. The ligaments of focus include the anterior cruciate ligament, the posterior cruciate ligament, the medial collateral ligament, the posterolateral corner, the anterolateral ligament, and the medial patellofemoral ligament.