OBJECTIVE To describe the indications, rationale, techniques, alternatives, contraindications, complications, and efficacy of lumbar and caudal epidural corticosteroid injections. METHODS Case reports and retrospective and prospective studies were extensively reviewed to provide detailed descriptions of the clinical features of lumbar and caudal epidural corticosteroid injections. RESULTS Epidural corticosteroid injections are commonly requested treatments for patients with various low-back or lower-extremity pain syndromes (or both). Most of the reports on the use of this type of treatment are retrospective and noncontrolled. These studies indicate benefit; however, the prospective controlled studies provide varied results about the efficacy of lumbar and caudal epidural corticosteroid injections. CONCLUSIONS A thorough analysis of the few available controlled studies and their limitations indicates that this treatment is probably efficacious for patients with certain lower-extremity radicular pain syndromes when intermediate-term (2 weeks to 3 months) results are assessed after injection. More studies are needed to elucidate further the most beneficial candidates and techniques.