Methods: Seventy five patients with acute discogenic pain were included in the study.The patients were randomly assigned to three groups. All patients received a single epidural dose of triamcinolone [80 mg] and 12.5 mg bupivacaine combination. The patients in Group 1, Group 2 and Group 3 received a volume of 10 mL, 15 mL, and 20 mL by epidural injections, respectively. The efficacy of treatment was assessed with VAS (visual analog scale) [O= no pain, 10 = unbearable pain], SLET(straight leg elevation test) [0° = worst, 85° = best], and Oswestry Disability Index; ODI [0% to 20%:minimal disability , 80% to 100%:bed bound patients] before and 2 weeks after the EPSI.