Radiograph remains an important diagnostic tool for detection of musculoskeletal diseases despite recent advances in computed tomography (CT) or magnetic resonance imaging (MRI). Many musculoskeletal disorders are primarily diagnosed by identifying characteristic features on radiographs, which are known to have diagnostic value. In addition, radiographs provide basic information for determining the necessity of cross-sectional imaging such as CT or MRI. Therefore, radiologists should be aware of the radiographic findings of musculoskeletal diseases and they should apply them to establish the diagnosis. This article presents a review of the important radiographic findings that enable the diagnosis of musculoskeletal diseases of the lower extremity.