Background: Epidural steroid therapy has been well-established for the treatment of sciatica and low back pain. Disappointing results following surgical decompression or discectomy have led to wide trials of corticosteroids injected either systemically or into the intraspinally. Although epidural steroid is known to be very effective in the treatment of the patients with low back pain, few data showed the therapeutic duration of epidural steroid. Methods: We studied 120 patients who were treated with epidural steroid for the treatment of low back pain or sciatica or both. We retrospectively analysed the duration of analgesia, number of injections per each session, and complications. Results: The duration of analgesia ranged from 17 days to 300 days, and the mean duration was $73.7{pm}70.5$ (SD) days. The mean number of injections per each session was $1.8{pm}1.3$ (range: 1 to 12). There were no significant complications with epidural steroid injections. Conclusions: One to three epidural steroid injections at one week interval leads more than two months of pain relief without significant complications.