AbstractBackground: Interlaminar and trans-foraminal epidural steroid injections are commonly performed interventions in managing low backache with lumbosacral radicular pain.However, controversy exists to the superiority of one over the other. Material and Methods: Sixty six patients with low back ache with unilateral single level lumbar radiculopathy were randomly allocated to group IL (interlaminar approach)and group TF (trans-foraminal approach).In group IL needle was placed in epidural space by loss of resistance technique and in group TF, needle was placed in epidural space under C-arm guidance. In both the groups, Omnipaque ® (Iohexol) radio contrast dye was used for confirmation of correct placement of respective needles. A solution of 1 ml (40 mg) triamcinolone with 3 ml of normal saline was injected into the epidural space. The primary outcome measure was pain relief at the end of 2nd and 3rd week. Secondary outcome measures werestraight leg raising test (SLRT),reduction inanalgesic use, reversal of paraesthesia and subjective improvement in walking tolerance.Results : In Group IL ,NRS score decreased from preprocedural score of 7.77±1.2 to 4.73±1.1 and 4.27±1.5 at the end of 2nd and 3rd week post procedure respectively. Where as in Group TF,NRS score decreased from preprocedural score of 7.8±1.3 to 2.77±1.7 and 2.63 ±1.7 at the end of 2nd and 3rd week respectively. This difference in NRS score was statistically significant both at the end of 2nd week and 3rd week with Group TF having better pain relief. There was no statistically significant difference among the 2 groups with respect to improvement of SLRT and walking tolerance, reduction in analgesic use and reversal of paraesthesia at the end of 3rd week. Conclusion: Epidural steroid injection by transforaminal approach provides better subjective pain relief than interlaminar approach in the short term.