BACKGROUND: This study describes the authors' experience with patients who received an epidural steroid injection (ESI) for lumbosciatica with radicular leg pain as predominant symptom. We analyzed the efficacy of ESI according to duration of pain and history of prior lumbar spine surgery. METHODS: One hundred thirty-six patients who had low back pain with radicular symptoms were included. Each patient was given 10 ml of 1% mepivacaine mixed with 40 mg of methylprednisolone every two weeks until at least a 75% improvement or reduction in pain was seen. We recommended no more than 3 injections within 3 months. RESULTS: Three to six months after the first injection the more favorable results were observed in patients with subacute radicular leg pain (less than 3 months' duration)(87.6 - 75%, good-excellent) and chronic leg pain with no prior surgery (greater than 3 months' duration)(84.8 - 71%, good-excellent) than in patients with chronic leg pain with prior surgery (50 - 40.1%, good-excellent). The efficacy of ESI was decreased after 1 year after the first ESI. CONCLUSIONS: ESI was effective in the management of lumbosacral radicular pain regardless of duration of symptoms. However, patient's who had had prior lumbar spine surgery had the least satisfactory results.