We previously reported that facet fusion (FF) using a percutaneous pedicle screw (PPS) system, as a minimally invasive evolution of posterolateral fusion (PLF), yielded favorable clinical outcomes for degenerative lumbar spondylolisthesis (DLS). This study aimed to evaluate the 10-year postoperative clinical outcomes of FF. Eighty-nine of 143 consecutive patients (mean age, 66.6 years; follow-up rate, 62.2%) who underwent FF for single-level DLS were retrospectively reviewed after a minimum follow-up of 10 years. Therapeutic effectiveness was assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), Roland-Morris Disability Questionnaire (RMDQ), and visual analogue scale (VAS) preoperatively and at 1 and 10 years postoperatively. The revision surgery rate was also evaluated. The therapeutic effectiveness rates determined by the JOABPEQ slightly declined across all domains from 1 to 10 years postoperatively; however, high effectiveness was maintained, with rates of 73.8% for Low Back Pain and 77.9% for Walking Ability. Although mean RMDQ and VAS scores increased slightly compared with those at 1 year postoperatively, favorable outcomes were preserved at 10 years. No statistically significant differences were observed between VAS scores for low back pain or buttock and lower limb pain at 1 and 10 years postoperatively. Eight patients required revision surgery for adjacent segment disease between 1 and 10 years after the initial surgery, resulting in a revision rate of 5.6%. No patients required revision surgery for early postoperative complications or unsatisfactory clinical outcomes. FF provided sustained clinical benefits at 10 years postoperatively. The 10-year revision rate of 5.6% was extremely low compared with previously reported rates after interbody fusion. Given that RMDQ and VAS scores remained favorable, the reduced 10-year postoperative therapeutic effectiveness in Walking Ability assessed by the JOABPEQ may reflect age-related functional decline rather than a deterioration in surgical outcomes. Low back pain did not worsen 10 years after in situ fusion. These findings suggest that FF is a useful option for the long-term management of DLS.