STUDY DESIGN: Prospective cohort study. OBJECTIVES: The purpose of this study was to identify preoperative factors associated with clinically meaningful improvement, patient satisfaction and expectation fulfilment at 2 years follow-up in patients undergoing single-level TLIF for degenerative spondylolisthesis. METHODS: Patients who underwent a primary, single-level TLIF for degenerative spondylolisthesis between 2006 and 2015 were identified from a prospectively maintained institutional spine registry. Baseline characteristics and PROMs including the Oswestry Disability Index (ODI), 36-Item Short-Form Physical Component Score (SF-36 PCS), Mental Component Score (SF-36 MCS), Visual Analogue Scale (VAS) back pain, and VAS leg pain were collected preoperatively, at 1 month, 3 months, 6 months, and 2 years. RESULTS: A total of 997 patients were included. Multivariate analyses showed that increasing age (OR 1.039, < .001) and better preoperative ODI (OR .984, = .018) were associated with achieving minimal clinically important difference (MCID) for VAS Back. Increasing age (OR 1.032, = .007) and better preoperative VAS Back (OR .783, < .001) were associated with achieving MCID for VAS Leg. Lower BMI (OR .952, = .024) and better preoperative ODI (OR .976, < .001) were associated with achieving MCID for SF-36 PCS. Importantly, a better preoperative SF-36 MCS was associated with MCID attainment for ODI (OR 1.038, < .001), satisfaction (OR 1.034, < .001) and expectation fulfilment (OR 1.024, < .001). CONCLUSION: Patients who were older, have less preoperative disability and better preoperative mental health were significantly more likely to attain clinically meaningful improvement in PROMs and postoperative satisfaction after single-level TLIF. Identification of these factors would aid surgeons in patient selection and surgical counselling for single-level TLIF.