The unilateral biportal endoscopic (UBE) technique is less invasive and has a faster recovery time than open surgery. Compared with the uniportal technique, the biportal technique has a larger field of vision and a wider operation range.We attempted the posterior UBE approach for cervical stenosis at the C4-C6 levels. UBE decompression of C4-C6 with unilateral lateral mass screw fixation at the C4-C5 levels was performed under general anesthesia.We successfully performed cord decompression at the C4-C6 levels using the UBE technique. This approach could be used as an alternative method to treat cervical stenosis with instability.