Part II of this two-part article reviews differential diagnosis of common geriatric knee disorders. Differentiating extra-articular from intra-articular causes of knee pain is stressed, since treatments and prognoses can be quite different. Referred pain from the ipsilateral hip and spine should also be kept in mind. The diagnostic approach to knee pain can be categorized anatomically and according to etiology: Is the pain coming from the bone (patella, femur, tibia, fibula), or the soft tissue (ligament, tendon, capsule, synovium, meniscus, muscle)? Is it degenerative, inflammatory, metabolic, traumatic, infectious, or neoplastic? These issues are included in the discussion.