Obesity is a risk factor for severe, radicular, and debilitating lumbosacral pain. The use of non-surgical treatment methods in obese patients is important. Epidural steroid injection (ESI) is a common procedure that helps patients with low back pain and radicular symptoms. So far, using ESI in patients with Lumbar herniated discs remains to be controversial among physicians. Thus, the current study was carried out to compare the therapeutic effects of ESI's in obese and non-obese patients with spinal disc herniation. This prospective, clinical trial study was conducted among 124 patients (58=non-obese, 66=obese) with low back pain caused by a Lumbar herniated disc, who referred to our Pain Clinic from 2017 to 2018. The ESI was done using the parasagittal inter-laminar approach. The severity of pain was measured by the patients’ self-report of pain and using the visual analog scale (VAS) before the treatment and two and six weeks after the treatment. The Oswestry Disability Index (ODI) was also measured in the treatment groups. Patients were followed for 6 weeks (IRCT20131124015515N3). Overall, 58 (46. 8%) patients had a BMI of 20-25 kg/m2, 38 (30. 6%) had a BMI of 25-30 kg/m2, and 28 (22. 6%) patients had a BMI of >30 kg/m2. The changes in the pain scores and ODI at different time periods showed no statistically significant differences in the two groups (P=0. 685, P=0. 995), respectively. The ESI is an effective, safe, minimally invasive, and cost-effective method that can result in pain relief and improvements in patients' function after a short period of time. Hence, we suggested that this treatment be considered for all patients with acute/chronic low back pain as well as radiculopathy.