Lumbar disc herniation is a common cause of back and radicular leg pain. A bulging annulus and contained herniated disc can compress a nearby exiting root as it enters the neuroforamen and may cause pain and neurological symptoms. Percutaneous laser disc decompression (PLDD) has been regarded as an effective alternative to microdiscectomy for the treatment of contained lumbar disc herniations. However, there is no consensus regarding the type of laser to use, the ideal wavelength, or the energy applied. The ideal laser irradiation should have a high water absorption coefficient and low tissue pervasion, to limit thermal injury. The 1470 nm wavelength of the diode laser is absorbed by water 40 times more effectively than the 980 nm wavelength. We conducted this study to evaluate the efficacy and safety of PLDD using a 1470 nm diode laser. We retrospectively reviewed the clinical data of 27 patients with radicular pain who underwent PLDD for the treatment of contained lumbar disc herniation during a 12-month period. The 1470 nm diode laser produces smaller local lesions, but greater tissue variations around the nucleus pulposus. This higher affinity for water lessens the formation of a carbonization zone, which results in less thermal injury of the adjacent nervous tissue. According to the MacNab criteria, 85.2% of the cases were improved at 6-month follow-up. Pain decreased from VAS 8.1 preoperatively to VAS 3.1 postoperatively. There is no consensus in the international literature regarding the ideal wavelength. Our results support the conclusion that PLDD using a 1470 nm diode laser is a safe and effective minimally invasive technique for patients with radicular pain affected by contained herniated lumbar discs.