Low back pain with radiating pain to the hip, buttock, or limb is the most common reason for electrodiagnostics referral. Electrodiagnostics is used to assess for lumbosacral radiculopathy potentially underlying low back pain. It serves as an extension of the clinical history and physical examination, and complements neuroimaging. Common low back pathologies amenable to electrodiagnostic evaluation include lumbosacral disk herniation and spinal stenosis. Electrodiagnostics may aid in the decision-making process when considering surgical management, and may aid in patient selection. The usefulness of electrodiagnostics is maximized when performed for the appropriate patient, and when the findings are properly interpreted.