One hundred and fifty-four cases of single level degenerative lumbar spinal stenosis were randomly allocated to receive a unilateral biportal endoscopic discectomy (UBE; n=77) or a tubular microendoscopic discectomy (TME; n=77). The outcomes of interest included the Oswestry Disability Index (ODI), the Zurich Claudication Questionnaire (ZCQ), patient satisfaction using the Modified Macnab Criteria, length of stay (admission period), operative time, and estimated blood loss. Outcomes were assessed over a 24 month time period. Results revealed superior ODI and ZCQ scores in the UBE group throughout the 24 month follow up period compared to the TME group. Patient satisfaction was higher in the UBE group. The UBE group also had shorter admission period, operative time, and estimated blood loss compared to the TME group.