Many authors have reported no significant differences in clinical outcomes between posterolateral fusion (PLF) and interbody fusion, as well as satisfactory long-term outcomes after PLF. Facet fusion (FF), a minimally invasive evolution of PLF, has also resulted in good clinical outcomes. This study aimed to assess the clinical outcomes 5 years after FF for degenerative lumbar spondylolisthesis (DLS) and determine whether good clinical outcomes were maintained after FF. Records of 115 patients who underwent FF for single-level DLS with at least 5 years of follow-up were retrospectively studied. The therapeutic effectiveness of FF was assessed as a clinical outcome using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), the Roland-Morris Disability Questionnaire (RMDQ), and the visual analogue scale (VAS) preoperatively and at 1 and 5 years postoperatively. Computed tomography was performed for fusion confirmation. The revision surgery rate was also evaluated. The JOABPEQ category scores demonstrated therapeutic effectiveness in 81.7% of patients at 1 year postoperatively and 81.4% of patients at 5 years postoperatively for low back pain; the corresponding proportions for walking ability were 93.8% and 86.6%, respectively. There were no significant differences in therapeutic effectiveness at 1 and 5 years postoperatively for any category, including the RMDQ and VAS scores. The fusion rate was 90.4% at the final follow-up. Four patients required revision surgery for adjacent segment disease 1-5 years after the first surgery (revision surgery rate, 3.5%). Good clinical outcomes were maintained 5 years after FF, and FF had an extremely low revision surgery rate.