Context:Magnetic resonance imaging (MRI) affords high-resolution visualization of the soft tissue structures (menisci, ligaments, cartilage, etc) and bone marrow of the knee.Evidence Acquisition:Pertinent clinical and research articles in the orthopaedic and radiology literature over the past 30 years using PubMed.Results:Ligament tears can be accurately assessed with MRI, but distinguishing partial tears from ruptures of the anterior cruciate ligament (ACL) can be challenging. Determining the extent of a partial tear is often extremely difficult to accurately assess. The status of the posterolateral corner structures, menisci, and cartilage can be accurately evaluated, although limitations in the evaluation of certain structures exist. Patellofemoral joint, marrow, tibiofibular joint, and synovial pathology can supplement physical examination findings and provide definitive diagnosis.Conclusions:MRI provides an accurate noninvasive assessment of knee pathology.