Abstract Background The European Organisation for Research and Treatment of Cancer (EORTC) quality of life questionnaire for non-muscle invasive bladder cancer (QLQ-NMIBC24) has been available and applied for some years now, but has yet to undergo a full comprehensive psychometric evaluation. The aim of this study was to investigate the psychometric properties of the Dutch version of the EORTC QLQ-NMIBC24 questionnaire in patients with low, intermediate and high risk NMIBC. Methods We included patients newly diagnosed with NMIBC participating in the multicenter, population-based prospective cohort studies UroLife or BlaZIB. Psychometric evaluation included examination of the structural validity, reliability (i.e. internal consistency and test–retest reliability), construct validity (i.e. divergent validity and known-groups validity), responsiveness and interpretability. Results A total of 1463 patients who completed the baseline questionnaire of UroLife (n = 541, response rate 50%) or BlaZIB (n = 922, ...