Background: Lumbar transforaminal epidural steroid injections (TFESIs) are performed to provide symptom relief in patients with radicular pain. Recent articles suggested that injected volume itself have analgesic effects and higher volumes are associated with better outcomes. To date, few studies have been conducted to investigate the effects of volume. Therefore, well-designed controlled studies were necessary to confirm the effect of volume itself on pain relief. The purpose of this study was to examine the effectiveness of a forceful saline injection on lumbar TFESI using non-particulate steroids. Methods: Fifty consecutive patients with lumbar radicular pain were enrolled. The participants were allocated into one of two groups: dexamethasone with volume (Group DV) and dexamethasone alone (Group DO). The volume was delivered by a forceful injection of 5ml of normal saline. The primary end-point for this study was a VAS pain score and modified MacNab score indicating the rate of effectiveness at the four-week follow-up. Results: There were no significant post-procedural VAS differences between two groups (P = .252). The effectiveness rate among the patients was 47.8% in DV group, 34.8% in DO group, measured by modified MacNab score. The difference was not statistically significant (P = .117). Conclusions: A forceful saline injection did not have a significant effect during the treatment of radicular pain. Further studies with greater volumes and with additional techniques would offer a more conclusive perspective.