All patients presenting with signs and symptoms of lumbar radiculopathy must undergo a thorough history taking and physical examination. Often, however, the diagnosis remains unclear; it is accurate anatomically, but the underlying cause of the lesion is not confirmed, or the symptoms are so severe that more information on the anatomy is required. Therefore, the next step in the diagnostic process is imaging studies. This article discusses imaging modalities, including plain radiographs, magnetic resonance imaging, computed tomography (CT), CT myelogram, selective nerve root block, and bone scan.