Tracheobronchomalacia (TBM) is defined as an excessive collapse of the intrathoracic trachea. Bronchoscopy is the gold standard to diagnose TBM, but bronchoscopy has major disadvantages, such as general anaesthesia. Cine-CT is a non-invasive alternative to diagnose TBM, but its use in children is restricted by ionizing radiation. Our aim was to evaluate the feasibility of spirometer-controlled cine-MRI as alternative to cine-CT in a retrospective study.12 children (mean 12 years, range 7-17), suspected to have TBM, underwent cine-MRI. Static scans were acquired at end-inspiration and expiration covering the thorax using a 3D SPGR sequence. 3D-Dynamic-scans were performed covering only the central airways. TBM was defined as a decrease of the trachea or bronchi diameter greater than 50% at end-expiration in the static and dynamic scans.The success rate of the cine-MRI protocol was 92%. Cine-MRI was compared with bronchoscopy or chest-CT in 7 subjects. TBM was diagnosed by cine-MRI in 7 out of 12 children (58%) and was confirmed by bronchoscopy or CT. In 4 patients, cine-MRI demonstrated tracheal narrowing that was not present in the static scans.Spirometer-controlled cine-MRI is a promising technique to assess TBM in children and has the potential to replace bronchoscopy.