A chest X-ray (CXR) is routinely performed after percutaneous dilatational tracheostomy (PDT). The purpose of this study was to evaluate the diagnostic yield of routine CXR following PDT and its impact on patient management and to identify predictors of post-PDT CXR changes. Two-hundred-and-thirty-nine patients who underwent PDT in a 21-bed intensive care unit were included prospectively in the study. The following data were collected: patient demographics, APACHE III scores, pre-PDT FiO2 and PEEP, PDT technique, perioperative complications and the use of bronchoscopic guidance. We compared post-PDT CXR with the last pre-PDT CXR. We documented any post-PDT new radiographic findings including atelectasis, pneumothorax, pneumomediastinum, surgical emphysema, pulmonary infiltrates or tracheostomy tube malposition. We also recorded management modifications based on post-PDT radiographic changes, including increased PEEP, chest physiotherapy, therapeutic bronchoscopy or chest tube insertion. Atelectasis was the only new finding detected on post-PDT CXRs of 24 (10%) patients. The new radiographic findings resulted in a total of 14 modifications of management in 10 (4%) patients including increased PEEP in six, chest physiotherapy in six and bronchoscopy in two patients. Trauma and pre-PDT PEEP >5 cmH2O were independent predictors of post-PDT CXR changes. Routine CXR following PDT has a low diagnostic yield, detecting mainly atelectasis and leading to a change in the management in only a minority ofpatients. Routine CXR after apparently uncomplicated PDT performed by an experienced operator may not be necessary and selective use may improve its diagnostic yield. Further studies are required to validate the safety of selective versus routine post-PDT CXR.