Internal derangement is the most common temporomandibular joint disorder. Degenerative osteoarthritis and trauma are next in frequency. Less common pathology includes rheumatoid arthritis, synovial chondromatosis, calcium pyrophosphate dehydrate deposition disease, pigmented villonodular synovitis, tumors, infection, and osteonecrosis. We provide a systematic approach to facilitate interpretation based on major anatomic structures: disc-attachments, joint space, condyle, and lateral pterygoid muscle. Relevant graphic anatomy and state of the art imaging are discussed in correlation with current clinical and therapeutic highlights of pathologic entities affecting the joint.