To evaluate the level of concurrence between radiologist reports and the diagnosis of community-acquired pneumonia (CAP) in patients discharged from an emergency department (ED), a retrospective chart audit of patients discharged with a diagnosis of 'pneumonia' or 'possible pneumonia' from the ED during a 2-year period was conducted. Emergency physician (EP) and radiology report (RR) diagnoses were categorized as 'pneumonia', 'possible pneumonia', 'non-pneumonia' and 'normal', and categories from each were compared. 815 charts were analyzed. Of 671 EP diagnoses of 'pneumonia', 304 (45.3%) RR's reported 'pneumonia' and 82 (12.2%), 'possible pneumonia'. Of 815 EP diagnoses of 'pneumonia' or 'possible pneumonia', 426 (52.3%) RRs were in agreement, while 216(26.5%) were of diagnoses other than pneumonia and 173 (21.1%) were read as normal. EPs and radiologists frequently disagree on whether a patient has pneumonia or not. Perhaps it is time to revisit the gold standard status of plain chest X-ray.