Use of a contralateral sublaminar endoscopic approach may minimize facet violation and better visualize the dura and cystic lesions during operation. The aim of this study was to introduce a surgical technique for contralateral sublaminar endoscopic removal of lumbar juxtafacet cysts using a percutaneous biportal endoscopic approach. Ten cases of lumbar juxtafacet cyst were consecutively treated via a contralateral sublaminar endoscopic approach using percutaneous biportal endoscopic surgery. Postoperative magnetic resonance imaging scans were evaluated on postoperative day 1 for optimal removal of cysts and neural decompression status. Clinical findings were evaluated in preoperative and postoperative periods using a visual analog scale for leg pain and the Oswestry Disability Index. Ten lumbar juxtafacet cysts in 10 patients were treated using the contralateral sublaminar biportal endoscopic approach. Postoperative magnetic resonance imaging depicted complete removal of juxtafacet cysts and optimal neural decompression of treated segments in all patients. Preoperative visual analog scale and Oswestry Disability Index scores improved significantly after surgery: visual analog scale scores changed from 7.64 ± 0.71 preoperatively to 1.63 ± 1.28 at last follow-up visit (P < 0.05), and Oswestry Disability Index scores changed from 45.35 ± 16.15 to 15.82 ± 10.21 (P < 0.05). Mean operative time was 60.1 ± 23.4 minutes. A contralateral sublaminar approach using percutaneous biportal endoscopy may be an alternative treatment for symptomatic lumbar juxtafacet cysts. This approach may minimize iatrogenic facet violation and traumatization of posterior musculoligamentous structures.