OBJECTIVES: Transforaminal epidural steroid injection (TFESI) is widely used to manage lumbosacral radicular pain due to herniated lumbar disc (HLD). OBJECTIVES: We evaluated the long-term outcomes of TFESI in patients with lumbosacral radicular pain due to an HLD by the location, type, and size of the HLD. METHODS: In total, 114 patients who received the initial TFESI at least 4 years ago completed a telephone interview. We investigated the presence of radicular pain, degree of current pain, current pain medications and TFESIs, additional TFESIs, progression to surgery, and trouble in performing daily life activities and occupational job duties. We classified the included patients by the location, type, and size of the HLD, and evaluated whether these factors affected the long-term outcomes of TFESI. RESULTS: At least 4 years after the initial TFESI, radicular pain was completely resolved in 45% of the patients. However, 30% patients were on oral painkillers or repetitive TFESIs or had undergone surgery and 15% had difficulty in performing daily life activities and occupational job duties. A larger number of patients with extruded lumbar disc herniation required additional TFESIs than those with protruded lumbar disc herniation. Apart from this, the outcomes did not significantly differ by the location, type, and size of the HLD. CONCLUSIONS: Our findings provide useful information to clinicians managing radicular pain due to HLD.