BACKGROUND Transforaminal endoscopic lumbar discectomy (TELD), a minimally invasive spinal technique, has advantages over open discectomy. Unilateral TELD for disc herniation causing bilateral symptoms is challenging. In this study, we describe a percutaneous endoscopic herniotomy technique by using a unilateral approach for lumbar disc herniation with bilateral obvious symptoms. METHODS From June 2014 to October 2015, 26 patients who had back as well as bilateral leg pain and/or weakness due to lumbar disc herniation were treated by TELD with a unilateral approach. Clinical outcomes were evaluated via a visual analogue scale (VAS; 0-10), and functional status was assessed with the Oswestry Disability Index (0-100%) postoperatively and 3 and 12 months postoperatively. Surgical satisfaction rate was assessed during the final follow-up. RESULTS The mean VAS for leg pain on the operative side improved from preoperative 8.39 ± 1.84 to 2.18 ± 1.26 postoperatively, 1.96 ± 0.83 at 3 months postoperatively, and 2.05 ± 1.42 at 1 year postoperatively (P < 0.01). The mean VAS for leg pain on the contralateral was 7.12 ± 1.74 and improved to 1.57 ± 1.66 postoperatively, 1.22 ± 1.58 at 3 months postoperatively, and 1.15 ± 1.35 at 1 year postoperatively (P < 0.01). The mean preoperative Oswestry Disability was 83.63 ± 8.49, with 23.58 ± 7.24 at 1 week postoperatively, 19.81 ± 11.26 at 3 months postoperatively, and 17.54 ± 13.40 at 12 months postoperatively (P < 0.01). Good or excellent global results were obtained in 96.2% of patients. CONCLUSIONS TELD can be effective for lumbar disc herniation causing bilateral symptoms, through one working channel.