The article discusses the standardisation of spirometry, a key diagnostic tool in respiratory medicine, aiming to ensure consistent and accurate measurements across different settings. Edited by V. Brusasco, R. Crapo, and G. Viegi, the document outlines the essential aspects of spirometry, including definitions, equipment requirements, test procedures, and quality control measures. It emphasizes the importance of standardising spirometry to improve the reliability of results and facilitate accurate diagnosis and monitoring of respiratory conditions. The document covers the forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), along with other derived indices like FEF25-75% and peak expiratory flow (PEF). It details the procedures for conducting spirometry tests, including the criteria for acceptable test performance, such as a satisfactory start of the test and a plateau in the volume-time curve at the end of the test. The article also addresses quality control for spirometry equipment, the importance of calibration checks, and the need for proper training of personnel. Additionally, it includes guidelines for reversibility testing, which involves assessing the response to bronchodilators, and provides recommendations for the use of different types of devices and techniques. The document concludes with a comprehensive overview of the key elements necessary for the accurate and reliable performance of spirometry, ensuring that the results are meaningful for clinical decision-making.The article discusses the standardisation of spirometry, a key diagnostic tool in respiratory medicine, aiming to ensure consistent and accurate measurements across different settings. Edited by V. Brusasco, R. Crapo, and G. Viegi, the document outlines the essential aspects of spirometry, including definitions, equipment requirements, test procedures, and quality control measures. It emphasizes the importance of standardising spirometry to improve the reliability of results and facilitate accurate diagnosis and monitoring of respiratory conditions. The document covers the forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), along with other derived indices like FEF25-75% and peak expiratory flow (PEF). It details the procedures for conducting spirometry tests, including the criteria for acceptable test performance, such as a satisfactory start of the test and a plateau in the volume-time curve at the end of the test. The article also addresses quality control for spirometry equipment, the importance of calibration checks, and the need for proper training of personnel. Additionally, it includes guidelines for reversibility testing, which involves assessing the response to bronchodilators, and provides recommendations for the use of different types of devices and techniques. The document concludes with a comprehensive overview of the key elements necessary for the accurate and reliable performance of spirometry, ensuring that the results are meaningful for clinical decision-making.