Background: The QoR-15 is a patient-reported outcome questionnaire that measures the quality of recovery after surgery and anaesthesia. We aimed to perform a systematic review and meta-analysis of the measurement properties of the QoR-15. Methods: Studies reporting measurement properties or interpretability of the QoR-15 after surgery were eligible for inclusion. All languages were included in the PubMed and Embase search. The COSMIN guidelines for systematic reviews of patient-reported outcome measurements were followed. Criteria for good measurement properties outlined in the consensus-based guidelines for selecting outcome measurement instruments for clinical trials were applied. A metaanalysis and synthesis of data across studies was performed. Results: Nine hundred and thirty-three titles were identified, and six articles were included in the study. The study population comprised 1548 patients undergoing a variety of surgical elective procedures. The QoR-15 was validated in English, Danish, Chinese, and Portuguese. High-quality evidence for good content validity, good internal consistency (Cronbach's α of 0.836), and essential unidimensionality of the QoR-15 as a measurement of postoperative quality of recovery was found. There was at least moderate-quality evidence of good reliability of the QoR-15 (intraclass correlation of 0.989) and good error of measurement (standard error of measurement of 1.85). The upper 95% confidence limit of the smallest detectable change was 3.63, and the minimal clinical important difference was 8.0. Conclusions: The QoR-15 fulfils requirements for outcome measurement instruments in clinical trials and is the first measurement instrument of postoperative quality of recovery to undergo a systematic review according to the COSMIN checklist.