BACKGROUND: Lumbar spinal stenosis (LSS) reduces walking and quality of life. It is the main indication for spinal surgery in older people yet 40% report walking disability post-operatively. Identifying the prognostic factors of post-operative walking capacity could aid clinical decision-making, guide rehabilitation and optimise health outcomes. OBJECTIVE: To synthesise the evidence for pre-operative mutable and immutable prognostic factors for post-operative walking in adults with LSS. DESIGN: Systematic review with narrative synthesis. METHODS: Electronic databases (CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science, OpenGrey) were searched for observational studies, evaluating factors associated with walking after surgery in adults receiving surgery for LSS from database inception to January 2020. Two reviewers independently evaluated studies for eligibility, extracted data and assessed risk of bias (Quality in Prognosis Studies). The Grading of Recommendations Assessment, Development and Evaluation method was used to determine level of evidence for each factor. RESULTS: 5526 studies were screened for eligibility. Thirty-four studies (20 cohorts, 9,973 participants, 26 high, 2 moderate, 6 low risk of bias) were included. Forty variables (12 mutable) were identified. There was moderate quality of evidence that pre-operative walking capacity was positively associated with post-operative walking capacity. The presence of spondylolisthesis and the severity of stenosis were not associated with post-operative walking capacity. All other factors investigated had low/very low level of evidence. CONCLUSION: Greater pre-operative walking is associated with greater post-operative walking capacity but not spondylolisthesis or severity of stenosis. Few studies have investigated mutable prognostic factors that could be potentially targeted to optimise surgical outcomes.