Ogilvie, VKersten, P2026-03-052026-03-052015-03-01New Zealand Journal of Physiotherapy, 43(1).http://hdl.handle.net/10292/20726The Nijmegen Questionnaire is commonly used by physiotherapists and other health professionals in clinical and research settings. This outcome measure was developed by researchers at the Nijmegen University in the Netherlands as a screening tool for the hyperventilation syndrome in the 1980s. However, the literature that supports the efficacy of its use is scarce. This paper examines the evidence in relation to the conceptual basis, validity, and reliability of the Nijmegen Questionnaire. A systematic review of the literature was carried out to identify studies that are related to the above measurement properties for the questionnaire. Studies identified were evaluated for their methodological qualities using the COSMIN checklist. The clinical utility of this instrument is also discussed. Issues associated with the development and validating process of this outcome measure are identified. There is also a lack of evidence in cultural validation given that the Nijmegen Questionnaire was developed in the Netherlands. While this is the only questionnaire currently available that is designed specifically for the screening of hyperventilation syndrome, administrators need to be aware of the issues identified in relation to validity and reliability when interpreting the results. Applying more robust validating processes to establish the efficacy of the Nijmegen Questionnaire appears to be a priority for researchers to improve the quality of health services for individuals suffering from hyperventilation syndrome.The New Zealand Journal of Physiotherapy is registered on Scopus, and since 2012, has offered Open Access publication of all content. Present and future journal articles are freely accessible as well as past journals that have been published from 2012 onwards. There are no author fees for publication.1103 Clinical Sciences4201 Allied health and rehabilitation scienceNijmegen questionnaireHyperventilationOutcome measurementReliabilityValidityA Critical Review of the Psychometric Properties of the Nijmegen Questionnaire for Hyperventilation SyndromeJournal ArticleOpenAccess10.15619/NZJP/43.1.01