The intradiscal high-pressure injection of saline and lidocaine (IDHP) is a minimally invasive percutaneous procedure for a lumbar intervertebral disc extrusion. The purpose of this study was to investigate the clinical outcomes of IDHP in terms of pain relief, reduction of disability, and risk of complications. Thirty patients with primarily radicular pain due to an extrusion-type disc herniation who underwent IDHP were enrolled in the study. A visual analogue pain scale (VAS) and the Japanese Orthopedic Association (JOA) scoring system for the treatment of low back disorders were used at pre-treatment, 2 weeks post-treatment, and 3 months post-treatment. The mean VAS decreased significantly (p < 0.01) from 64.3 mm at pre-treatment to 26.3 mm at 2 weeks post-treatment and 15.5 at 3 months post-treatment. The mean JOA score improved significantly (p < 0.01) from 14.7 to 21.3 at 2 weeks post-treatment and 24.6 at 3 months post-treatment. IDHP appeared to produce significant effects in patients with radicular pain, leading to the improvement of VAS and JOA scores. IDHP appears to be a safe, minimally invasive treatment option for a lumbar intervertebral disc extrusion.